Mysoline (primidone) dosage, indications, interactions, side effects and more (2023)

Primidone decreases the level or effect of abemaciclib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Co-administration of abemaciclib with strong CYP3A4 inducers decreases plasma concentrations of abemaciclib and its metabolites.

Primidone decreases the level or effect of acalabrutinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of acalabrutinib with strong CYP3A inducers. If a strong CYP3A inducer must be used, increase the acalabrutinib dose to 200 mg twice daily.

Primidone decreases the level or effect of adagrasib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.Adagrasib increases the level or effect of primidone by affecting the metabolism of the liver enzyme CYP2C9/10. Avoid or use an alternative medication. Avoid co-administration of adagrasib, a CYP2C9 inhibitor, with sensitive CYP2C9 substrates unless otherwise recommended in the prescribing information for those substrates.

Primidone decreases the level or effect of alosetron by affecting the metabolism of the liver enzyme CYP1A2. Avoid or use an alternative medication.

Primidone decreases the level or effect of alpelisib through pharmacodynamic synergism. Avoid or use an alternative medication. Avoid co-administration of alpelisib (CYP3A4 substrate) with strong CYP3A4 inducers.Primidone decreases the level or effect of alpelisib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of alpelisib (CYP3A4 substrate) with strong CYP3A4 inducers.

Primidone decreases the effects of antithrombin alfa by increasing its metabolism. Avoid or use an alternative medication.

Primidone decreases the effects of antithrombin III by increasing its metabolism. Avoid or use an alternative medication.

Primidone decreases the level or effect of apixaban by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. contraindicated.

Primidone decreases the level or effect of apremilast by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Concomitant use with strong CYP inducers leads to a significant decrease in the systemic availability of apremilast, which may result in a loss of efficacy

Primidone decreases the effects of argatroban by increasing metabolism. Avoid or use an alternative medication.

Primidone decreases the level or effect of avapritinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone lowers axitinib levels by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Selection of concomitant medicinal products with no or minimal CYP3A4 induction potential is recommended.

Primidone decreases the level or effect of bedaquiline by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid concomitant use of bedaquiline with strong CYP3A4 inducers as the therapeutic effect may be reduced

Primidone decreases the effects of bemiparin by increasing its metabolism. Avoid or use an alternative medication.

benzhydrocodone/acetaminophen, primidone. One increases the toxicity of the other through pharmacodynamic synergism. Avoid or use an alternative medication. Concomitant administration can result in severe sedation, respiratory depression, coma and death. Reserve the concomitant prescription of these drugs for patients for whom other treatment options are inadequate. Limit dosages and duration to the minimum required. Pay close attention to signs of respiratory depression and sedation.

Primidone lowers berotralstat levels through the P-glycoprotein (MDR1) efflux transporter. Avoid or use an alternative medication.

Primidone decreases the effects of bivalirudin by increasing its metabolism. Avoid or use an alternative medication.

Primidone decreases bosutinib levels by affecting hepatic/intestinal CYP3A4 enzyme metabolism. Avoid or use an alternative medication. Strong CYP3A4 inducers decreased bosutinib plasma concentrations by ~85%.

Bremelanotide decreases the level or effect of primidone by others (see comment). Avoid or use an alternative medication. Bremelanotide may slow gastric emptying and potentially decrease the rate and extent of absorption of concomitant oral medications. Avoid use if taking oral medications that depend on threshold concentrations for efficacy. The interactions listed are representative examples and do not encompass all possible clinical examples.

Primidone decreases the level or effect of brigatinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Concomitant use with strong CYP3A4 inducers may reduce the efficacy of brigatinib.

Primidone decreases the level or effect of cabozantinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of cabozantinib with strong CYP3A4 inducers. If a strong CYP3A4 inducer is required, increase the cabozantinib dose by 40 mg/day (Cometriq) or by 20 mg/day (Cabometyx). Resume the previous dose 2-3 days after stopping the strong CYP3A4 inducer.

Primidone, calcium/magnesium/potassium/sodium oxybates. One enhances the action of the other through pharmacodynamic synergism. Avoid or use an alternative medication. Concomitant administration can result in severe sedation, respiratory depression, coma and death. Reserve the concomitant prescription of these drugs for patients for whom other treatment options are inadequate. Limit dosages and duration to the minimum required. Pay close attention to signs of respiratory depression and sedation.

Primidone decreases the level or effect of capmatinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases ceritinib levels by affecting hepatic/intestinal CYP3A4 enzyme metabolism. Avoid or use an alternative medication.

Primidone decreases the level or effect of citalopram by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of cobicistat by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. contraindicated.

Primidone decreases the level or effect of copanlisib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of copanlisib with strong CYP3A4 inducers.

Primidone decreases the level or effect of crizotinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of dabigatran through the P-glycoprotein (MDR1) efflux transporter. Avoid or use an alternative medication. Avoid co-administration. P-gp inducers reduce systemic dabigatran exposure

Primidone decreases dabrafenib levels by increasing metabolism. Avoid or use an alternative medication. Strong CYP2C8 inducers may decrease dabrafenib levels.Primidone decreases dabrafenib levels by affecting hepatic/intestinal CYP3A4 enzyme metabolism. Avoid or use an alternative medication.

Primidone decreases the effects of dalteparin by increasing its metabolism. Avoid or use an alternative medication.

Primidone decreases the level or effect of dantrolene by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of daridorexant by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of darolutamide by others (see comment). Avoid or use an alternative medication. Darolutamide is a P-gp and CYP3A4 substrate. Avoid co-administration of darolutamide with a combination of P-gp and strong or moderate CYP3A4 inducers.

Primidone decreases the level or effect of deflazacort by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid concomitant use of deflazacort with moderate or strong CYP3A4 inducers.

Primidone decreases the level or effect of dihydroergotamine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of intranasal dihydroergotamine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of diltiazem by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of dronedarone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of duloxetine by affecting the metabolism of the liver enzyme CYP1A2. Avoid or use an alternative medication.

Primidone decreases the level or effect of duvelisib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Co-administration with a strong CYP3A inducer decreases the area under the curve (AUC) of duvelisib, which may reduce the efficacy of duvelisib.

Primidone decreases the level or effect of edoxaban through the P-glycoprotein (MDR1) efflux transporter. Avoid or use an alternative medication. Avoid concomitant use of edoxaban with strong P-gp inducers

Primidone decreases the level or effect of elacestrant by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of eliglustat by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Strong CYP3A inducers significantly decrease eliglustat exposure; Co-administration not recommended

Primidone decreases the level or effect of elvitegravir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid; Co-administration with CYP3A inducers may result in decreased plasma concentrations of elvitegravir and/or a co-administered protease inhibitor, leading to loss of therapeutic effect and possible resistance

Primidone decreases the level or effect of encorafenib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the effects of enoxaparin by increasing its metabolism. Avoid or use an alternative medication.

Primidone decreases the level or effect of entrectinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of enzalutamide by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of erdafitinib by altering its metabolism. Avoid or use an alternative medication. Avoid co-administration of strong CYP2C9 or CYP3A4 inducers with erdafitinib.

Primidone decreases the level or effect of ergotamine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of erythromycin base by affecting hepatic/intestinal CYP3A4 enzyme metabolism. Avoid or use an alternative medication.

Primidone decreases the level or effect of erythromycin ethyl succinate by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of erythromycin lactobionate by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of erythromycin stearate by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of eszopiclone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of ethinyl estradiol by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. The effectiveness of hormonal contraceptives may be reduced. The use of a non-hormonal contraceptive is recommended.

Primidone decreases the level or effect of ethosuximide by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of everolimus by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of fedratinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. The effect of co-administration of a strong CYP3A4 inducer with fedratinib has not been studied.

Primidone increases the level or effect of fexinidazole by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. CYP450 inducers can significantly increase plasma concentrations of the active metabolites of fexinidazole: fexinidazole sulfoxide (M1) and fexinidazole sulfone (M2). M2 plasma levels associated with increased risks of QT prolongation.

Primidone decreases the level or effect of finerenone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of flurazepam by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of inhaled fluticasone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the effect of fondaparinux by increasing its metabolism. Avoid or use an alternative medication.

Primidone decreases the level or effect of fostamatinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of ganaxolone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of ganaxolone with moderate or strong CYP3A4 inducers. If concomitant administration is unavoidable, an increase in the ganaxolone dose should be considered; However, do not exceed the maximum daily dose for weight.

Primidone decreases the level or effect of glasdegib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of glasdegib with strong CYP3A inducers.

Primidone decreases the level or effect of glecaprevir/pibrentasvir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the effects of heparin by increasing its metabolism. Avoid or use an alternative medication.

hydrocodone, primidone. One increases the toxicity of the other through pharmacodynamic synergism. Avoid or use an alternative medication. Concomitant administration can result in severe sedation, respiratory depression, coma and death. Reserve the concomitant prescription of these drugs for patients for whom other treatment options are inadequate. Limit dosages and duration to the minimum required. Pay close attention to signs of respiratory depression and sedation.

Primidone lowers ibrutinib levels by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Strong CYP3A inducers decrease plasma concentrations of ibrutinib ~10-fold.

Primidone decreases the level or effect of idelalisib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. avoid co-administration; Strong CYP3A4 inducers significantly decrease systemic idelalisib exposure

Primidone decreases the level or effect of infigratinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of irinotecan by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of irinotecan liposomal by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of istradefylline by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid concomitant use of istradefylline with strong CYP3A4 inducers.

Primidone decreases the level or effect of ivabradine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of ivabradine with moderate CYP3A4 inducers.

Primidone decreases ivacaftor levels by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid concomitant administration with strong CYP3A4 inducers; Systemic ivacaftor exposure significantly reduced (ie ~9-fold).

Primidone decreases the level or effect of ivosidenib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Co-administration of ivosidenib with strong CYP3A4 inducers decreased ivosidenib plasma concentrations.

Primidone decreases the level or effect of ixazomib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of ixazomib with strong CYP3A inducers. Strong inducers have been shown to decrease ixazomib Cmax by 54% and AUC by 74%.

Primidone decreases the level or effect of larotrectinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. If co-administration of larotrectinib with strong CYP3A4 inducers is unavoidable, double the larotrectinib dose. Resume previous larotrectinib dose once CYP3A4 inducer has been discontinued for 3-5 half-lives

Primidone decreases the level or effect of lefamulin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid concomitant use of lefamulin with strong or moderate CYP3A inducers unless the benefits outweigh the risks. Watch out for reduced effectiveness.

Primidone decreases the level or effect of lemborexant by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of leniolisib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone increases the concentration or effect of letermovir by others (see comment). Avoid or use an alternative medication. Co-administration of letermovir with UCT1A1/3 inducers is not recommended.Primidone decreases the level or effect of letermovir through the P-glycoprotein (MDR1) efflux transporter. Avoid or use an alternative medication. Co-administration of letermovir with P-gp inducers is not recommended.

Primidone decreases the level or effect of lomitapide by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of losartan by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of lovastatin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of lumateperone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of lurbinectedin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of macimorelin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Possible false positive test results with concomitant use of Macimorelin and strong CYP3A4 inducers. Discontinue strong CYP3A4 inducers prior to testing and allow for adequate washout time.

Primidone decreases the level or effect of macitentan by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of macitentan with strong CYP3A4 inducers

Primidone lowers mestranol levels by increasing metabolism. Avoid or use an alternative medication. Contraceptive failure can result.

Primidone increases methoxyflurane toxicity by increasing metabolism. contraindicated. Increased metabolism of methoxyflurane to nephrotoxic compounds.

Primidone, metoclopramide intranasally. One enhances the effect of the other by the other (see comment). Avoid or use an alternative medication. Comment: Avoid intranasal use of metoclopramide or interacting drugs, depending on the importance of the drug to the patient.

Primidone decreases the level or effect of midostaurin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Strong CYP3A4 inducers can decrease midostaurin concentrations, resulting in decreased efficacy.

Primidone decreases the level or effect of mobocertinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of naldemedine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration with strong CYP3A4 inducers.

Primidone decreases the level or effect of nefazodone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of neratinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of neratinib with strong/moderate CYP3A4 inducers.

Primidone decreases the level or effect of netupitant/palonosetron by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Netupitant is primarily metabolised by CYP3A4; Avoid use in patients chronically using a strong CYP3A4 inducer

Primidone lowers levels of nintedanib through the P-glycoprotein (MDR1) efflux transporter. Avoid or use an alternative medication. Avoid concomitant administration, especially with P-gp inducers that are also CYP3A4 inducers; Nintedanib is a substrate of P-gp and to a lesser extent CYP3A4.

Primidone decreases the level or effect of norethindrone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration unless the benefit outweighs the risk. With simultaneous use, hormonal contraceptives are not a reliable method of effective contraception. Concomitant use may increase the occurrence of menstrual-related side effects (amenorrhea, dysmenorrhea, menorrhagia).

Primidone decreases the level or effect of norethindrone acetate by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration unless the benefit outweighs the risk. With simultaneous use, hormonal contraceptives are not a reliable method of effective contraception. Concomitant use may increase the occurrence of menstrual-related side effects (amenorrhea, dysmenorrhea, menorrhagia).

Primidone decreases the level or effect of norethindrone transdermally by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration unless the benefit outweighs the risk. With simultaneous use, hormonal contraceptives are not a reliable method of effective contraception. Concomitant use may increase the occurrence of menstrual-related side effects (amenorrhea, dysmenorrhea, menorrhagia).

Primidone decreases the level or effect of olaparib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of olaparib with strong CYP3A4 inducers.

Intranasal primidone and olopatadine both increase sedation. Avoid or use an alternative medication. Concomitant administration increases the risk of CNS depression, which can lead to additional impairment of psychomotor performance and impairment of time of day.

Primidone decreases the level or effect of olutasidenib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Strong or moderate CYP3A inducers decrease plasma concentrations and efficacy of olutasidenib (a CYP3A4 substrate).

Primidone decreases the level or effect of omaveloxolone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of osilodrostat by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of osimertinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of osimertinib with strong CYP3A inducers.

Primidone decreases the level or effect of ozanimod by others (see comment). Avoid or use an alternative medication. Co-administration of ozanimod (a CYP2C8 substrate) with strong CYP2C8 inducers decreases the exposure of the active metabolites (CC112273 and CC1084037) of ozanimod, which may reduce the efficacy of ozanimod. Therefore, co-administration of ozanimod with strong CYP2C8 inducers is not recommended.

Primidone decreases the level or effect of palbociclib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Potent CYP3A inducers decrease palbociclib plasma exposure by ~85%.

Primidone decreases the level or effect of pemigatinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of perampanel by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of pexidartinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the effects of phenindione by increasing metabolism. Avoid or use an alternative medication.

Primidone lowers pomalidomide levels by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.Primidone lowers pomalidomide levels by affecting the metabolism of the liver enzyme CYP1A2. Avoid or use an alternative medication.

Primidone lowers ponatinib levels by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid unless concomitant administration outweighs the possible risk of ponatinib underexposure; monitor for signs of reduced effectiveness.

Primidone decreases the level or effect of pralsetinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. If this is not possible, double the current pralsetinib dose starting on day 7 of co-administration with a strong CYP3A inducer. After stopping the inducer for at least 14 days, resume the previous dose of pralsetinib.

Primidone decreases the level or effect of pretomanid by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Pretomanid is a CYP3A4 substrate. Avoid co-administration of strong or moderate CYP3A4 inducers.

Primidone decreases the level or effect of primaquine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the effects of protamine by increasing metabolism. Avoid or use an alternative medication.

Primidone decreases the level or effect of ranolazine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of ribociclib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Concomitant use of ribociclib with strong CYP3A inducers should be avoided.

Primidone decreases the level or effect of rifabutin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of rimegepant by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of ripretinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Co-administration with a strong CYP3A inhibitor decreases the systemic exposure to ripretinib and its active metabolite (DP-5439), which may reduce the risk of side effects.

Primidone decreases the level or effect of rivaroxaban by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. contraindicated.

Primidone decreases the level or effect of rolapitant by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Long-term co-administration of strong CYP3A4 inducers with rolapitant may significantly reduce the efficacy of rolapitant.

Primidone decreases the level or effect of romidepsin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Ropeginterferon alfa 2b and primidone both increase other (see comment). Avoid or use an alternative medication. Narcotics, hypnotics, or tranquilizers can produce additive neuropsychiatric side effects. Avoid use and monitor patients receiving the combination for effects of excessive CNS toxicity.

selinexor, primidone. unspecified interaction mechanism. Avoid or use an alternative medication. Neurological toxicity may occur in patients treated with selinexor. Avoid taking Selinexor with other medications that may cause dizziness or confusion.

Primidone decreases the level or effect of selpercatinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of selumetinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of sildenafil by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Strong CYP3A4 inducers are expected to cause significant decreases in sildenafil plasma levels

Primidone decreases the level or effect of silodosin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of simvastatin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of siponimod by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Co-administration of siponimod with a drug that produces moderate CYP2C9 and moderate or strong CYP3A4 induction is not recommended. Co-administration with moderate or strong CYP3A4 inducers alone is not recommended in patients with CYP2C9*1/*3 and *2/*3 genotype.

Primidone decreases the level or effect of sirolimus by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

primidone, sodium oxybate. Both enhance the action of the other through pharmacodynamic synergism. Avoid or use an alternative medication. Concomitant administration can result in severe sedation, respiratory depression, coma and death. Reserve the concomitant prescription of these drugs for patients for whom other treatment options are inadequate. Limit dosages and duration to the minimum required. Pay close attention to signs of respiratory depression and sedation.

Primidone decreases the level or effect of sofosbuvir/velpatasvir through the P-glycoprotein (MDR1) efflux transporter. Avoid or use an alternative medication. Sofosbuvir and velpatasvir are substrates of the drug transporter P-gp. Potent P-gp inducers can significantly decrease sofosbuvir and velpatasvir plasma concentrations, resulting in a possible reduced therapeutic effect.Primidone decreases the level or effect of sofosbuvir/velpatasvir by affecting the metabolism of the liver enzyme CYP2B6. Avoid or use an alternative medication. Velpatasvir is a substrate of CYP2B6, CYP2C8 and CYP3A4. Medicinal products that are moderate to strong inducers of CYP2B6, CYP2C8 or CYP3A4 may significantly decrease velpatasvir plasma concentrations, resulting in a possible reduced therapeutic effect.Primidone will decrease the level or effect of sofosbuvir/velpatasvir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Velpatasvir is a substrate of CYP2B6, CYP2C8 and CYP3A4. Medicinal products that are moderate to strong inducers of CYP2B6, CYP2C8 or CYP3A4 may significantly decrease velpatasvir plasma concentrations, resulting in a possible reduced therapeutic effect.

Primidone decreases the level or effect of sonidegib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of sonidegib with strong or moderate CYP3A4 inducers.

Primidone decreases the level or effect of sorafenib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of sotorasib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of sparsentan by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of stiripentol by affecting the metabolism of the liver enzyme CYP1A2. Avoid or use an alternative medication. If concomitant use of stiripentol with strong CYP1A2 inducers cannot be avoided, increase the dose of stiripentol.Primidone decreases the level or effect of stiripentol by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Sufentanil SL, primidone. One increases the toxicity of the other through pharmacodynamic synergism. Avoid or use an alternative medication. Concomitant administration can result in hypotension, severe sedation, respiratory depression, coma and death. Reserve the concomitant prescription of these drugs for patients for whom other treatment options are inadequate. Limit dosages and duration to the minimum required. Pay close attention to signs of respiratory depression and sedation.

Primidone decreases the level or effect of tamsulosin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of tazemetostat by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of teniposide by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of tetracycline by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of tezacaftor by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of tiagabine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of tivozanib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of tizanidine by affecting the metabolism of the liver enzyme CYP1A2. Avoid or use an alternative medication.

Primidone decreases the level or effect of tolvaptan by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of trabectedin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of tucatinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.Primidone decreases the level or effect of tucatinib by others (see comment). Avoid or use an alternative medication. Co-administration of tucatinib (a CYP2C8 substrate) with a strong or moderate CYP2C8 inducer decreases tucatinib plasma concentrations.

Primidone decreases the level or effect of ubrogepant by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of ulipristal by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of upadacitinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid co-administration of upadacitinib with strong CYP3A4 inducers.

Primidone decreases the level or effect of valbenazine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Simultaneous use is not recommended.

Primidone decreases the level or effect of velpatasvir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of vemurafenib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of venetoclax by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Avoid concomitant use of venetoclax with strong or moderate CYP3A inducers. Consider alternative treatment with agents that have less CYP3A induction.

Primidone decreases the level or effect of voclosporin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of vonoprazan by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases vorapaxar levels by affecting hepatic/intestinal CYP3A4 enzyme metabolism. Avoid or use an alternative medication.

Primidone lowers voriconazole levels by increasing metabolism. contraindicated.Primidone decreases the level or effect of voriconazole by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. contraindicated.

Primidone decreases the levels or effects of vortioxetine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of voxelotor by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication. Voxelotor is primarily metabolised by CYP3A4. Avoid co-administration with moderate or strong CYP3A4 inducers. If co-administration cannot be avoided, increase the voxelotor dose (see Dose Modifications).

Primidone decreases the level or effect of voxilaprevir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases the level or effect of zanubrutinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Avoid or use an alternative medication.

Primidone decreases abiraterone levels by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Avoid concomitant use of abiraterone with strong CYP3A4 inducers; If a strong CYP3A4 inducer must be used, increase abiraterone dosing frequency from once daily to twice daily.

Primidone lowers acebutolol levels by increasing metabolism. Use caution/monitoring. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Acrivastine and primidone both increase sedation. Use caution/monitoring.

Primidone increases and albuterol decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone and alfentanil both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of almotriptan by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of alprazolam by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.Primidone and alprazolam both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of amiodarone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Amisulpride and primidone both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of amitriptyline by affecting the metabolism of the liver enzyme CYP2C19. Use caution/monitoring.Primidone decreases the level or effect of amitriptyline by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely.Primidone and amitriptyline both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of amlodipine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Amobarbital and primidone both increase sedation. Use caution/monitoring.

Primidone and amoxapine both increase sedation. Use caution/monitoring.

Primidone and apomorphine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of aprepitant by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone increases and arformoterol decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone decreases the level or effect of aripiprazole by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.Primidone and aripiprazole both increase sedation. Use caution/monitoring.

Primidone increases and armodafinil decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Asenapine and primidone both increase sedation. Use caution/monitoring.

Asenapine transdermal and primidone both increase sedation. Use caution/monitoring.

Primidone lowers atenolol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone decreases the level or effect of atogepant by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. The recommended dose of atogepant when used concomitantly with strong or moderate CYP3A4 inducers is 30 mg or 60 mg qDay.

Primidone decreases the level or effect of atorvastatin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of avanafil by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. In patients with ED, carefully monitor response as efficacy may be reduced.

Avapritinib and primidone both enhance sedation. Use caution/monitoring.

Primidone decreases the level or effect of avatrombopag by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. In the treatment of ITP, co-administration of avatrombopag with a moderate or strong dual CYP2C9/3A4 inducer requires an increased starting dose of avatrombopag. Refer to the drug monograph for specific recommendations.

Azelastine and primidone both increase sedation. Use caution/monitoring.

Primidone and baclofen both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of bazedoxifene/conjugated estrogens by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and belladonna and opium both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of belumosudil by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Belumosudil dosage to 200 mg p.o. Increase twice daily when co-administered with strong CYP3A inducers.

Primidone lowers bendamustine levels by affecting the metabolism of the liver enzyme CYP1A2. Use caution/monitoring. Concentrations of active metabolites may be increased.

Primidone and benperidol both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of benzhydrocodone/acetaminophen by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Caution when stopping CYP3A4 inducers co-administered with benzhydrocodone (prodrug of hydrocodone); Hydrocodone plasma concentrations may increase and lead to potentially fatal respiratory depression.

Primidone increases and benzphetamine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone lowers betaxolol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone lowers bisoprolol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Blinatumomab increases primidone levels by decreasing metabolism. Modify/monitor therapy closely. The initiation of treatment causes a transient release of cytokines that can suppress CYP450 enzymes; The highest risk of drug-drug interactions is during the first 9 days of cycle 1 and the first 2 days of cycle 2 in patients receiving concomitant CYP450 substrates, particularly in patients with a narrow therapeutic index.

Primidone decreases the level or effect of bortezomib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of brentuximab vedotin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Brexanolone, Primidone.Ether increases the toxicity of the other by sedation. Use caution/monitoring.

Primidone decreases the level or effect of brexpiprazole by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Double dose of brexpiprazole for 1-2 weeks when administered with a strong CYP3A4 inducer.

Brodalumab, primidone. Other (see comment). Use caution/monitoring. Comment: The formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; thus, brodalumab may normalize the formation of CYP450 enzymes. Monitoring of the therapeutic effect should be considered when initiating or discontinuing brodalumab in patients concomitantly receiving CYP450 substrates, particularly in patients with a narrow therapeutic window.

Primidone decreases the level or effect of bromocriptine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Brompheniramine and primidone both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of budesonide by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone, bupivacaine implant. One increases the toxicity of the other by others (see comment). Use caution/monitoring. Comment: Local anesthetics may increase the risk of methemoglobinemia when concomitantly exposed to drugs that also cause methemoglobinemia.

Primidone and buprenorphine both increase sedation. Use caution/monitoring.Primidone decreases the level or effect of buprenorphine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and buprenorphine buccal both increase sedation. Use caution/monitoring.Primidone decreases the level or effect of buprenorphine buccally by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the concentration or effect of the subdermal buprenorphine implant by affecting hepatic/intestinal CYP3A4 enzyme metabolism. Modify/monitor therapy closely. Patients already receiving a subdermal buprenorphine implant who require reinitiation of CYP3A4 inducer therapy should be monitored for signs and symptoms of withdrawal. If the dose of the concomitant CYP3A4 inducer cannot be reduced or discontinued, removal of the implant may be necessary and the patient should then be placed on a buprenorphine dosage form that allows for dose adjustment. If a CYP3A4 inducer is discontinued in a patient stabilized on buprenorphine, the patient should be monitored for overmedication.

Primidone decreases the concentration or effect of long-acting buprenorphine injection by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Patients transitioning from transmucosal buprenorphine concomitantly with CYP3A4 inducers to long-acting buprenorphine injection should be monitored to ensure that plasma levels of buprenorphine are adequate. If the buprenorphine dose is inadequate and the CYP3A4 inducer cannot be reduced or discontinued, switch the patient back to a buprenorphine formulation that allows for dose adjustment.

primidone, bupropion. increase in metabolism. Use caution/monitoring. Decrease levels of bupropion but increase levels of active metabolites. .

Primidone decreases the level or effect of buspirone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Butabarbital and primidone both increase sedation. Use caution/monitoring.

Butalbital and primidone both increase sedation. Use caution/monitoring.

Primidone and butorphanol both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of cabazitaxel by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Concomitant use of strong CYP3A4 inducers may decrease cabazitaxel concentrations. Avoid co-administration.

Primidone increases and caffeine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

primidone, calcifediol. Effects on the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Drugs that stimulate microsomal hydroxylation shorten the half-life of calcifediol.

Primidone decreases the level or effect of calcitriol by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of carbamazepine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Carbinoxamine and primidone both increase sedation. Use caution/monitoring.

Primidone and carisoprodol both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of carvedilol by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring.Primidone lowers carvedilol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone lowers celiprolol levels by increasing metabolism. Use caution/monitoring. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

cenobamate, primidone. Both enhance the effects of the other through sedation. Use caution/monitoring.

Primidone and chloral hydrate both increase sedation. Use caution/monitoring.

Chloramphenicol increases primidone levels by decreasing metabolism. Use caution/monitoring.

Primidone and chlordiazepoxide both increase sedation. Use caution/monitoring.Primidone decreases the level or effect of chlordiazepoxide by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of chloroquine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Chlorpheniramine and primidone both increase sedation. Use caution/monitoring.

Primidone and chlorpromazine both increase sedation. Use caution/monitoring.

Primidone and chlorzoxazone both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of cilostazol by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of cinacalcet by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Cinnarizine and primidone both increase sedation. Use caution/monitoring.

Clemastine and primidone both increase sedation. Use caution/monitoring.

primidone, clobazam. Other (see comment). Use caution/monitoring. Comment: Concomitant administration may increase the potential for CNS effects (e.g. increased sedation or respiratory depression).

Primidone decreases the level or effect of clomipramine by affecting the metabolism of the liver enzyme CYP1A2. Use caution/monitoring.Primidone decreases the level or effect of clomipramine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely.Primidone and clomipramine both increase sedation. Use caution/monitoring.

Primidone and clonazepam both increase sedation. Use caution/monitoring.

Primidone increases the level or effect of clopidogrel by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. CYP3A4 inducers may increase the metabolism of clopidogrel to its active metabolite. Monitor patients for a possible increase in anticoagulant effects when CYP3A4 inducers are used in combination with clopidogrel

Primidone and clorazepate both increase sedation. Use caution/monitoring.Primidone decreases the level or effect of clorazepate by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of clozapine by affecting the metabolism of the liver enzyme CYP1A2. Use caution/monitoring.Primidone decreases the level or effect of clozapine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.Primidone and clozapine both increase sedation. Use caution/monitoring.

Primidone and codeine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of colchicine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of conivaptan by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of conjugated estrogens by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of conjugated estrogens vaginally by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of cortisone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Cyclizine and primidone both increase sedation. Use caution/monitoring.

Primidone and cyclobenzaprine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of cyclophosphamide by affecting the metabolism of the liver enzyme CYP2B6. Use caution/monitoring.

Primidone decreases the level or effect of ciclosporin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Cyproheptadine and primidone both increase sedation. Use caution/monitoring.

Primidone and dantrolene both increase sedation. Use caution/monitoring.

Primidone and daridorexant both increase sedation. Modify/monitor therapy closely. Concomitant administration increases the risk of CNS depression, which can lead to additional impairment of psychomotor performance and impairment of time of day.

Primidone decreases the level or effect of darifenacin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of darunavir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of dasatinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and desipramine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of dexamethasone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Dexchlorpheniramine and primidone both increase sedation. Use caution/monitoring.

Primidone increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone decreases the level or effect of dexlansoprazole by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and dexmedetomidine both increase sedation. Use caution/monitoring.

Primidone increases and dexmethylphenidate decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone increases and dextroamphetamine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone and dextromoramide both increase sedation. Use caution/monitoring.

Primidone and diamorphine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of diazepam by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.Primidone and diazepam both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of diazepam intranasally by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Strong or moderate CYP3A4 inducers may increase diazepam elimination rate; therefore the effectiveness of diazepam may be reduced.Diazepam intranasally, primidone. One increases the effect of the other through pharmacodynamic synergism. Use caution/monitoring. Concomitant administration may potentiate the CNS depressant effects of each drug.

Primidone increases and diethylpropion decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Difelikefalin and primidone both increase sedation. Use caution/monitoring.

Primidone and Difenoxin hcl both increase sedation. Use caution/monitoring.

Dimenhydrinate and primidone both increase sedation. Use caution/monitoring.

Diphenhydramine and primidone both increase sedation. Use caution/monitoring.

Primidone and diphenoxylate HCl both increase sedation. Use caution/monitoring.

Primidone and dipipanone both increase sedation. Use caution/monitoring.

Primidone increases and dobutamine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone increases and dopamine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone increases and dopexamine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone and dosulepin both increase sedation. Use caution/monitoring.

Primidone and doxepin both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of doxorubicin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of liposomal doxorubicin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone lowers doxycycline levels by increasing metabolism. Use caution/monitoring.

Primidone and doxylamine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of dronabinol by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring. Dronabinol is a CYP2C9 substrate.Primidone decreases the level or effect of dronabinol by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Dronabinol is a CYP3A4 substrate.

Primidone and droperidol both increase sedation. Use caution/monitoring.

dulaglutide, primidone. Other (see comment). Use caution/monitoring. Comments: Dulaglutide slows gastric emptying and may impair the absorption of concomitant oral drugs; Be particularly careful with concomitant use with drugs with a narrow therapeutic index.

Dupilumab, primidone. Other (see comment). Use caution/monitoring. Comment: The formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; thus dupilumab could normalize the formation of CYP450 enzymes. Monitoring of the therapeutic effect should be considered when initiating or discontinuing dupilumab in patients concomitantly receiving CYP450 substrates, particularly in patients with a narrow therapeutic window.

Primidone decreases the level or effect of duvelisib through the P-glycoprotein (MDR1) efflux transporter. Use caution/monitoring.

Primidone decreases the level or effect of elagolix by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of eletriptan by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of eltrombopag by affecting the metabolism of the liver enzyme CYP1A2. Use caution/monitoring.Primidone decreases the level or effect of eltrombopag by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring.

Primidone decreases the level or effect of enfortumab vedotin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone increases and ephedrine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone increases and epinephrine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone increases and racemic epinephrine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone decreases the level or effect of erlotinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of escitalopram by affecting the metabolism of the liver enzyme CYP2C19. Use caution/monitoring.Primidone decreases the level or effect of escitalopram by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Esketamine intranasally, primidone. One increases the toxicity of the other through sedation. Modify/monitor therapy closely.

Primidone decreases the level or effect of eslicarbazepine acetate by increasing its metabolism. Use caution/monitoring. A higher dosage of eslicarbazepine may be required

Primidone lowers esmolol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone decreases the level or effect of esomeprazole by affecting the metabolism of the liver enzyme CYP2C19. Use caution/monitoring.

Primidone and estazolam both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of estradiol by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of estradiol vaginally by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of estrogen-conjugated synthetic drugs by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone lowers the level or effect of esterified estrogens by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of estropipate by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and ethanol both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of ethotoin by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring.Ethotoin enhances the effects of primidone by increasing metabolism. Use caution/monitoring. Phenytoin enhances the conversion of primidone to phenobarbital.

Etomidate and primidone both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of etonogestrel by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of etoposide by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of etravirine by affecting the metabolism of the liver enzyme CYP2C19. Use caution/monitoring.Primidone decreases the level or effect of etravirine by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring.Primidone decreases the level or effect of etravirine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of exemestane by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. For patients receiving exemestane with a strong CYP3A4 inducer, the recommended dose of exemestane is 50 mg daily after a meal.

Primidone decreases the level or effect of felbamate by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely.

Primidone decreases the level or effect of felodipine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone increases and fenfluramine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.Primidone decreases the level or effect of fenfluramine by others (see comment). Modify/monitor therapy closely. Concomitant use with drugs that increase serotonin levels may increase the risk of serotonin syndrome.

Primidone decreases the level or effect of fentanyl by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Concomitant use of fentanyl with CYP3A4 inducers could result in decreased fentanyl plasma concentrations, lack of efficacy, or possible development of a withdrawal syndrome in a patient who has developed physical dependence on fentanyl. After stopping a CYP3A4 inducer, plasma concentrations of fentanyl increase with decreasing effect of the inducer, which could enhance or prolong both the therapeutic effect and the side effects.

Primidone decreases the level or effect of fentanyl intranasally by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Concomitant use of fentanyl with CYP3A4 inducers could result in decreased fentanyl plasma concentrations, lack of efficacy, or possible development of a withdrawal syndrome in a patient who has developed physical dependence on fentanyl. After stopping a CYP3A4 inducer, plasma concentrations of fentanyl increase with decreasing effect of the inducer, which could enhance or prolong both the therapeutic effect and the side effects.

Primidone decreases the level or effect of transdermal fentanyl by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Concomitant use of fentanyl with CYP3A4 inducers could result in decreased fentanyl plasma concentrations, lack of efficacy, or possible development of a withdrawal syndrome in a patient who has developed physical dependence on fentanyl. After stopping a CYP3A4 inducer, plasma concentrations of fentanyl increase with decreasing effect of the inducer, which could enhance or prolong both the therapeutic effect and the side effects.

Primidone decreases the level or effect of fentanyl transmucosally by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Concomitant use of fentanyl with CYP3A4 inducers could result in decreased fentanyl plasma concentrations, lack of efficacy, or possible development of a withdrawal syndrome in a patient who has developed physical dependence on fentanyl. After stopping a CYP3A4 inducer, plasma concentrations of fentanyl increase with decreasing effect of the inducer, which could enhance or prolong both the therapeutic effect and the side effects.

iron maltol, primidone. One increases the concentration of the other through an unspecified interaction mechanism. Modify/monitor therapy closely. Concomitant administration of ferric maltol with certain oral drugs may decrease the bioavailability of ferric maltol and some oral drugs. For oral medicinal products where a reduction in bioavailability may have clinically significant impact on safety or efficacy, ferrous maltol should be administered separately from these medicinal products. The duration of separation may depend on the absorption of the co-administered drug (e.g. time to peak concentration, whether the drug is an immediate or extended release product).

Primidone decreases the level or effect of fesoterodine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of flibanserin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Strong CYP3A4 inducers decrease the systemic exposure of flibanserin significantly.

Primidone decreases the level or effect of fludrocortisone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and fluphenazine both increase sedation. Use caution/monitoring.

Primidone and flurazepam both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of fluticasone furoate by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone increases and formoterol decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone decreases the level or effect of fosamprenavir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of fosaprepitant by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of fosphenytoin by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring.Fosphenytoin enhances the effects of primidone by increasing metabolism. Use caution/monitoring. Phenytoin enhances the conversion of primidone to phenobarbital.

Primidone decreases the level or effect of gefitinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Increase gefitinib to 500 mg daily when co-administered with a strong CYP3A4 inducer. Resuming the gefitinib dose of 250 mg/day 7 days after stopping the strong inducer.

Primidone lowers glyburide levels by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring. Strong CYP2C9 inducers may increase glyburide metabolism.

Gotu kola enhances the effects of primidone through pharmacodynamic synergism. Use caution/monitoring. May increase CNS depression.

Primidone decreases the level or effect of guanfacine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Strong or moderate CYP3A4 inducers significantly reduce plasma concentrations and elimination half-life of guanfacine. When co-administered, more frequent dosing of the IR product may be required to achieve or maintain the desired hypotensive response. For patients with ADHD, the FDA-approved label for ER-guanfacine recommends that consideration should be given to doubling the recommended dose of guanfacine when co-administered.

guselkumab, primidone. Other (see comment). Use caution/monitoring. Comment: The formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; This normalizes the formation of CYP450 enzymes. Monitoring of the therapeutic effect should be considered when initiating or discontinuing guselkumab in patients concomitantly receiving CYP450 substrates, particularly in patients with a narrow therapeutic window.

Primidone and haloperidol both increase sedation. Use caution/monitoring.Primidone decreases the level or effect of haloperidol by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Hawthorn enhances the effects of primidone through pharmacodynamic synergism. Use caution/monitoring. May increase CNS depression.

Primidone decreases the effects of hemin through pharmacodynamic antagonism. Modify/monitor therapy closely. Drugs that increase delta-aminolevulinic acid synthetase may decrease hemin effects.

Hops enhance the effects of primidone through pharmacodynamic synergism. Use caution/monitoring. May increase CNS depression.

Primidone decreases the level or effect of hydrocodone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Caution when stopping CYP3A4 inducers co-administered with hydrocodone; Hydrocodone plasma concentrations may increase and lead to potentially fatal respiratory depression

Primidone decreases the level or effect of hydrocortisone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and hydromorphone both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of hydroxyprogesterone caproate (DSC) by affecting hepatic/intestinal CYP3A4 enzyme metabolism. Use caution/monitoring.

Hydroxyzine and primidone both increase sedation. Use caution/monitoring.

Primidone enhances the effects of ifosfamide by affecting the metabolism of the liver enzyme CYP2B6. Use caution/monitoring. Concomitant use of ifosfamide with CYP2B6 inducers may increase the metabolism of ifosfamide to its metabolite. In combination with CYP2B6 inducers, watch out for increased effects/toxicities.Primidone increases ifosfamide toxicity by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. CCYP3A4 inducers may increase the metabolism of ifosfamide to its active alkylating metabolites. CYP3A4 inducers may increase the formation of the neurotoxic/nephrotoxic ifosfamide metabolite chloroacetaldehyde. Patients taking ifosfamide concomitantly with CYP3A4 inducers should be closely monitored for toxicity and dose adjustment considered.

Primidone decreases the level or effect of iloperidone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.Primidone and iloperidone both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of imipramine by affecting the metabolism of the liver enzyme CYP1A2. Use caution/monitoring.Primidone decreases the level or effect of imipramine by affecting the metabolism of the liver enzyme CYP2C19. Use caution/monitoring.Primidone decreases the level or effect of imipramine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely.Primidone and imipramine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of indinavir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone increases and isoproterenol decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone decreases the level or effect of isosorbide dinitrate by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of isosorbide mononitrate by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of ixabepilone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Ixekizumab, primidone. Other (see comment). Use caution/monitoring. Comment: The formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; thus, ixekizumab may normalize the formation of CYP450 enzymes. Monitoring of the therapeutic effect should be considered when initiating or discontinuing ixekizumab in patients concomitantly receiving CYP450 substrates, particularly in patients with a narrow therapeutic index.

Kava enhances the effects of primidone through pharmacodynamic synergism. Use caution/monitoring. May increase CNS depression.

Ketamine and primidone both increase sedation. Use caution/monitoring.

Primidone and ketotifen, ophthalmic, both increase sedation. Use caution/monitoring.

Primidone lowers labetalol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone decreases lamotrigine levels by increasing hepatic clearance. Use caution/monitoring.

Primidone decreases the level or effect of lansoprazole by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of lapatinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

lasmiditan, primidone.One enhances the effect of the other by sedation. Use caution/monitoring. The concomitant use of Lasmiditan and other CNS depressants, including alcohol, has not been studied in clinical trials. Lasmiditan can cause sedation as well as other cognitive and/or neuropsychiatric side effects.

lemborexant, primidone.One enhances the effect of the other by sedation. Modify/monitor therapy closely. Dose adjustment may be required when lemborexant is co-administered with other CNS depressant medicinal products due to possible additive effects.

Primidone decreases the level or effect of lesinurad by affecting the metabolism of the liver enzyme CYP2C9/10. Modify/monitor therapy closely.

Primidone increases and levalbuterol decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone decreases the level or effect of levamlodipine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. No information is available on the quantitative effects of CYP3A4 inducers on amlodipine. Blood pressure must be closely monitored when amlodipine is co-administered with CYP3A4 inducers.

Primidone decreases intrauterine levonorgestrel levels by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases oral levonorgestrel levels by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of oral levonorgestrel/ethinylestradiol/iron bisglycinate by affecting hepatic/intestinal CYP3A4 enzyme metabolism. Modify/monitor therapy closely. The effectiveness of hormonal contraceptives may be reduced. Use an alternative method of contraception or a backup method when enzyme inducers are used with combined hormonal contraceptives (CHCs) and continue backup contraception for 28 days after stopping the enzyme inducer to ensure contraceptive effectiveness.

Primidone and levorphanol both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of lidocaine by affecting the metabolism of the liver enzyme CYP1A2. Use caution/monitoring.

Primidone increases the level or effect of linagliptin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. The use of alternative treatments is strongly recommended when linagliptin is to be co-administered with a CYP3A4 inducer

Primidone increases and lisdexamfetamine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone and lofepramine both increase sedation. Use caution/monitoring.

Primidone and lofexidine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of lopinavir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and loprazolem both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of loratadine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and lorazepam both increase sedation. Use caution/monitoring.

Primidone and lormetazepam both increase sedation. Use caution/monitoring.

Primidone and loxapine both increase sedation. Use caution/monitoring.

Inhaled primidone and loxapine both increase sedation. Use caution/monitoring.

Lurasidone, primidone.One increases the toxicity of the other by others (see comment). Use caution/monitoring. Comment: Potential for increased CNS depressant effects with concomitant use; Monitoring for increased side effects and toxicity.

Primidone and maprotiline both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of maraviroc by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and marijuana both increase sedation. Use caution/monitoring.Primidone decreases the level or effects of marijuana by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of medroxyprogesterone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Contraceptive failure possible. Use an alternative if available.

Primidone decreases the level or effect of mefloquine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and melatonin both increase sedation. Use caution/monitoring.

Primidone and meperidine both increase sedation. Use caution/monitoring.

Primidone and meprobamate both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of mestranol by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone increases and metaproterenol decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone and metaxalone both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of methadone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.Primidone and methadone both increase sedation. Use caution/monitoring.

Primidone increases and methamphetamine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone and methocarbamol both increase sedation. Use caution/monitoring.

Primidone increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Methylphenidate transdermally increases the level or effect of primidone by decreasing metabolism. Modify/monitor therapy closely. Consider reducing the dose of these drugs when given with methylphenidate. Watch for drug toxicity when starting or stopping methylphenidate.

Primidone decreases the level or effect of methylprednisolone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone lowers metoprolol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone decreases the level or effect of mexiletine by affecting the metabolism of the liver enzyme CYP1A2. Use caution/monitoring.

Primidone decreases the level or effect of midazolam by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.Primidone and midazolam both increase sedation. Use caution/monitoring.

intranasal midazolam, primidone. One increases the toxicity of the other through pharmacodynamic synergism. Modify/monitor therapy closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase the risk of hypoventilation, airway obstruction, desaturation, or apnea and contribute to a potent and/or prolonged drug effect.

Primidone increases and midodrine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone decreases the level or effect of mifepristone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. CYP3A4 inducers have not been studied, concomitant administration is not recommended by the manufacturer

Primidone and mirtazapine both increase sedation. Use caution/monitoring.Primidone decreases the level or effect of mirtazapine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of modafinil by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and morphine both increase sedation. Use caution/monitoring.

Primidone and motherwort both increase sedation. Use caution/monitoring.

Primidone and moxonidine both increase sedation. Use caution/monitoring.

Primidone and nabilone both increase sedation. Use caution/monitoring.

Primidone lowers nadolol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone and nalbuphine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of nateglinide by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring.

Primidone lowers nebivolol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering secobarbital. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone decreases the level or effect of nelfinavir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of nevirapine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of nicardipine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of nifedipine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely.

Primidone decreases the level or effect of nilotinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of nisoldipine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone increases and norepinephrine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone decreases the level or effect of norgestrel by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and nortriptyline both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of olanzapine by affecting the metabolism of the liver enzyme CYP1A2. Use caution/monitoring.Primidone and olanzapine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of oliceridine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. If co-administration with a CYP3A4 inducer is required, consider increasing the oliceridine dose until stable drug response is achieved; monitor for signs of opioid withdrawal. If the inducer is stopped, consider reducing the oliceridine dose and note signs of respiratory depression.

Primidone decreases the level or effect of omeprazole by affecting the metabolism of the liver enzyme CYP2C19. Use caution/monitoring.Primidone decreases the level or effect of omeprazole by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and opium tincture both increase sedation. Use caution/monitoring.

Oritavancin increases the level or effect of primidone by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring. Oritavancin is a weak CYP2C9 inhibitor; Caution with concomitant use with CYP2C9 substrates with a narrow therapeutic index

Orlistat lowers primidone levels by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Modify/monitor therapy closely. risk of cramps.

Primidone and orphenadrine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of osilodrostat by others (see comment). Modify/monitor therapy closely. Osilodrostat is a CYP3A4 and CYP2B6 substrate. Monitor cortisol levels and patient signs and symptoms during co-administration and withdrawal of strong CYP3A4 and/or CYP2B6 inducers. If necessary, adjust the dose of osilodrostat.

Primidone decreases ospemifene levels by affecting hepatic/intestinal CYP3A4 enzyme metabolism. Use caution/monitoring.Primidone lowers ospemifene levels by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring.

Primidone and oxazepam both increase sedation. Use caution/monitoring.

Primidone and oxycodone both increase sedation. Use caution/monitoring.Primidone lowers oxycodone levels by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and oxymorphone both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of paclitaxel by others (see comment). Use caution/monitoring. Paclitaxel levels/efficacy may decrease when co-administered with CYP2C8 inducers

Primidone decreases the level or effect of the paclitaxel protein bound by others (see comment). Use caution/monitoring. Paclitaxel levels/efficacy may decrease when co-administered with CYP2C8 inducers

Primidone and paliperidone both increase sedation. Use caution/monitoring.

Primidone and papaveretum both increase sedation. Use caution/monitoring.

Primidone and papaverine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of parecoxib by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring.

Passionflower enhances the effects of primidone through pharmacodynamic synergism. Use caution/monitoring. May increase CNS depression.

Primidone decreases the level or effect of pazopanib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone lowers penbutolol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone and pentazocine both increase sedation. Use caution/monitoring.

Pentobarbital and primidone both increase sedation. Use caution/monitoring.

Primidone and perphenazine both increase sedation. Use caution/monitoring.

Primidone increases and phendimetrazine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Phenobarbital and primidone both increase sedation. Use caution/monitoring.

Primidone increases and phentermine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone increases and phenylephrine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring. .

Primidone decreases the level or effect of phenytoin by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring.Phenytoin enhances the effects of primidone by increasing metabolism. Use caution/monitoring. Phenytoin enhances the conversion of primidone to phenobarbital.

Primidone and pholcodine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of pimavanserin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Avoid concomitant administration if possible. Watch out for reduced effectiveness of pimavanserin. An increase in pimavanserin dosage may be required.

Primidone and pimozide both increase sedation. Use caution/monitoring.

Primidone lowers pindolol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone increases and pirbuterol decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone decreases the level or effect of pitolisant by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Pitolisant exposure is reduced by 50% when co-administered with strong CYP3A4 inducers. For patients who remain stable on pitolisant 8.9 mg/day or 17.8 mg/day, double the pitolisant dose (ie 17.8 mg or 35.6 mg, respectively) over 7 days. If the strong CYP3A4 inducer is discontinued, reduce the pitolisant dose by half.

Primidone decreases the level or effect of polatuzumab vedotin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Polatuzumab undergoes catabolism to small peptides, amino acids, monomethylauristatin E (MMAE), and unconjugated MMAE-related catabolites. MMAE is a CYP3A4 substrate. Co-administration of polatuzumab vedotin with a strong CYP3A4 inducer may decrease the AUC of unconjugated MMAE.

Primidone lowers posaconazole levels by increasing metabolism. Use caution/monitoring.

Primidone decreases the level or effect of prednisolone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of prednisone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and prochlorperazine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of progesterone intravaginal gel by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of micronized progesterone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone lowers the level or effect of progesterone naturally by affecting hepatic/intestinal CYP3A4 enzyme metabolism. Use caution/monitoring.

Promethazine and primidone both increase sedation. Use caution/monitoring.

Primidone lowers propafenone levels by increasing metabolism. Use caution/monitoring.

Propofol and primidone both increase sedation. Use caution/monitoring.

Primidone lowers propranolol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone increases and propylhexedrine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone and protriptyline both increase sedation. Use caution/monitoring.

Primidone and quazepam both increase sedation. Use caution/monitoring.Primidone will decrease the level or effect of quazepam by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of quetiapine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.Primidone and quetiapine both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of quinidine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of ramelteon by affecting the metabolism of the hepatic enzyme CYP1A2. Use caution/monitoring.Primidone and Ramelteon both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of rasagiline by affecting the metabolism of the liver enzyme CYP1A2. Use caution/monitoring.

Primidone decreases the level or effect of repaglinide by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Rifampin lowers primidone levels by increasing metabolism. Use caution/monitoring.

Primidone decreases the level or effect of riociguat by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Dose adjustment data are not available

Primidone and risperidone both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of ritonavir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of ropinirole by affecting the metabolism of the liver enzyme CYP1A2. Use caution/monitoring.

Primidone lowers rufinamide levels by increasing metabolism. Use caution/monitoring.

Primidone decreases the level or effect of ruxolitinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of topical ruxolitinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone increases and salmeterol decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone decreases the level or effect of saquinavir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

sarilumab, primidone. Other (see comment). Use caution/monitoring. Comment: The formation of CYP450 enzymes can be altered by increased levels of cytokines such as IL-6. Elevated IL-6 concentration can downregulate CYP activity, such as in patients with RA, and therefore increase drug levels compared to individuals without RA. Blockade of IL-6 signaling by IL-6 antagonists (e.g. sarilumab) could reverse the IL-6 inhibitory effects and restore CYP activity, resulting in decreased drug concentrations. Caution when starting or stopping sarilumab when co-administered with CYP450 substrates, particularly those with a narrow therapeutic index.

Primidone and Scullcap both increase sedation. Use caution/monitoring.

Primidone and secobarbital both increase sedation. Use caution/monitoring.

secukinumab, primidone. Other (see comment). Use caution/monitoring. Comment: The formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; thus secukinumab could normalize the formation of CYP450 enzymes. Monitoring of the therapeutic effect should be considered when initiating or discontinuing secukinumab in patients concomitantly receiving CYP450 substrates, particularly in patients with a narrow therapeutic window.

Primidone decreases the level or effect of selexipag by increasing its metabolism. Modify/monitor therapy closely. Increase selexipag dose (up to 2-fold) when co-administered with strong CYP2C8 inducers.

Sevelamer lowers primidone levels by increasing excretion. Use caution/monitoring.

Sevoflurane and primidone both increase sedation. Use caution/monitoring.

Primidone and shepherd's purse both increase sedation. Use caution/monitoring.

Sodium sulfate/?magnesium sulfate/potassium chloride increases primidone toxicity to others (see comment). Use caution/monitoring. Comment: Co-administration with drugs that cause fluid and electrolyte abnormalities may increase the risk of side effects such as seizures, arrhythmias, and renal dysfunction.

Sodium sulfate/potassium sulfate/magnesium sulfate increases primidone toxicity to others (see comment). Use caution/monitoring. Comment: Co-administration with drugs that cause fluid and electrolyte abnormalities may increase the risk of side effects such as seizures, arrhythmias, and renal dysfunction.

Primidone decreases the level or effect of solifenacin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases sorafenib levels by increasing metabolism. Use caution/monitoring.

Primidone lowers sotalol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone and sufentanil both increase sedation. Use caution/monitoring.

Primidone decreases the effect of sufentanil SL by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Modify/monitor therapy closely. Concomitant administration of CYP3A4 inducers may decrease levels and efficacy of sufentanil and possibly induce a withdrawal syndrome in patients who have developed a physical dependence on sufentanil. Discontinuation of concomitantly administered CYP3A4 inducers may increase sufentanil plasma concentrations.

Primidone decreases the level or effect of sunitinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of suvorexant by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Strong CYP3A4 inducers may reduce the effectiveness of suvorexant; if an increased suvorexant dose is required, do not exceed 20 mg/day

Primidone decreases the level or effect of tacrolimus by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of tadalafil by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Avoid combination in patients with pulmonary HTN. In patients with ED, carefully monitor the response to tadalafil as its effectiveness may be reduced.

Primidone decreases the level or effect of tamoxifen by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring.Primidone decreases the level or effect of tamoxifen by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and tapentadol both increase sedation. Use caution/monitoring.

Primidone decreases the concentration or effect of tasimelteon by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Avoid concomitant use of tasimelteon with strong CYP3A4 inducers

Teclistamab increases the level or effect of primidone by altering metabolism. Use caution/monitoring. Teclistamab causes the release of cytokines that can suppress the activity of CYP450 enzymes, resulting in increased exposure of CYP substrates. Watch out for elevated levels or toxicities of sensitive CYP substrates. Adjust the dose of CYP substrate drug as needed.

Teduglutide increases primidone levels by others (see comment). Use caution/monitoring. Comment: Teduglutide may increase absorption of concomitant PO drugs; Caution with drugs that require titration or those with a narrow therapeutic index; Dose adjustment may be necessary.

Primidone and temazepam both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of temsirolimus by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of terbinafine by affecting the metabolism of the liver enzyme CYP1A2. Use caution/monitoring.Primidone decreases the level or effect of terbinafine by affecting the metabolism of the liver enzyme CYP2C9/10. Use caution/monitoring.Primidone decreases the level or effect of terbinafine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone increases and terbutaline decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Thalidomide potentiates the effects of primidone through an unspecified mechanism of interaction. Use caution/monitoring. Increased calming effect.

Primidone decreases the level or effect of theophylline by affecting the metabolism of the liver enzyme CYP1A2. Use caution/monitoring.Primidone decreases the levels or effects of theophylline by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and thioridazine both increase sedation. Use caution/monitoring.

Primidone and thiothixene both increase sedation. Use caution/monitoring.

Primidone decreases ticagrelor levels by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Avoid using ticagrelor with strong CYP3A inducers.

Primidone lowers timolol levels by increasing metabolism. Use caution/monitoring. Consider increasing the dose of beta-blockers while co-administering primidone. Atenolol, Sotalol, Nadolol are less likely to be affected than other beta-blockers.

Primidone decreases the level or effect of tinidazole by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of tipranavir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of tofacitinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Loss or decreased response to tofacitinib may occur when co-administered with strong CYP3A4 inducers

Primidone decreases the level or effect of tolterodine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone and topiramate both increase sedation. Modify/monitor therapy closely.

Primidone decreases toremifene levels by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. CYP3A4 inducers increase the rate of metabolism of toremifene and decrease steady-state serum concentrations.

Primidone and tramadol both increase sedation. Use caution/monitoring.Primidone decreases the level or effect of tramadol by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Decreased AUC of tramadol and the active metabolite (O-desmethyltramadol) when co-administered with strong CYP3A4 and CYP2B6 inducers

Primidone decreases the level or effect of trazodone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.Primidone and trazodone both increase sedation. Use caution/monitoring.

Primidone decreases the level or effect of the triamcinolone acetonide injectable suspension by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of triazolam by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.Primidone and triazolam both increase sedation. Use caution/monitoring.

Primidone and triclofos both increase sedation. Use caution/monitoring.

Primidone and trifluoperazine both increase sedation. Use caution/monitoring.

Primidone and trimipramine both increase sedation. Use caution/monitoring.

Triprolidine and primidone both increase sedation. Use caution/monitoring.

Trofinetide increases the level or effect of primidone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Monitor CYP3A4 substrates, for which a small increase in plasma concentration can result in severe toxicities when co-administered with trofinetide (a weak CYP3A4 inhibitor).

ustekinumab, primidone. Other (see comment). Use caution/monitoring. Comment: The formation of CYP450 enzymes can be altered by increased levels of certain cytokines during chronic inflammation; This normalizes the formation of CYP450 enzymes. Monitoring of the therapeutic effect should be considered when initiating or discontinuing ustekinumab in patients concomitantly receiving CYP450 substrates, particularly in patients with a narrow therapeutic window.

Valerian enhances the effects of primidone through pharmacodynamic synergism. Use caution/monitoring. May increase CNS depression.

Primidone decreases the level or effect of vardenafil by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of verapamil by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases the level or effect of inhaled vilanterol/fluticasone furoate by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring.

Primidone decreases vilazodone levels by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Use caution/monitoring. Consider increasing the vilazodone dose up to 2-fold (no more than 80 mg/day) when co-administered with strong CYP3A4 inducers for > 14 days.

Primidone reduces the effect of vitamin D by other (see comment). Use caution/monitoring. Comment: Vitamin D supplementation or dose adjustment may be required in patients receiving chronic anticonvulsant therapy.

Primidone increases vortioxetine levels by increasing metabolism. Modify/monitor therapy closely. Consider increasing the vortioxetine dose when co-administered with strong CYP inducers for > 14 days; Do not exceed three times the original vortioxetine dose.

Primidone decreases the level or effect of warfarin by affecting the metabolism of the liver enzyme CYP2C9/10. Modify/monitor therapy closely.

Primidone increases and xylometazoline decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone increases and yohimbine decreases sedation. Effect of interaction is not clear, be careful. Use caution/monitoring.

Primidone and ziconotide both increase sedation. Use caution/monitoring.

Primidone and ziprasidone both increase sedation. Use caution/monitoring.

Primidone and zotepine both increase sedation. Use caution/monitoring.

Primidone lowers acetaminophen levels by increasing metabolism. Minor/Meaning Unknown. Increased metabolism increases concentrations of hepatotoxic metabolites.

Primidone lowers paracetamol IV levels by increasing metabolism. Minor/Meaning Unknown. Increased metabolism increases concentrations of hepatotoxic metabolites.

Primidone decreases rectal paracetamol levels by increasing metabolism. Minor/Meaning Unknown. Increased metabolism increases concentrations of hepatotoxic metabolites.

Acetazolamide decreases primidone levels by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.acetazolamide, primidone. Mechanism: pharmacodynamic synergism. Minor/Meaning Unknown. Increased risk of anticonvulsant-induced osteomalacia.

Primidone decreases the level or effect of alfentanil by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of alfuzosin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of alosetron by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.Primidone decreases the level or effect of alosetron by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of ambrisentan by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

primidone, amitriptyline. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

primidone, amoxapine. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

Primidone decreases concentrations of amphotericin B deoxycholate by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.

Primidone decreases the level or effect of antipyrine by affecting the metabolism of the liver enzyme CYP1A2. Minor/Meaning Unknown.

Primidone decreases the level or effect of armodafinil by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of asenapine by affecting the metabolism of the liver enzyme CYP1A2. Minor/Meaning Unknown.

Ashwagandha enhances the effects of primidone through pharmacodynamic synergy. Minor/Meaning Unknown. May increase CNS depression.

Primidone decreases the level or effect of atazanavir by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the effect of atracurium through pharmacodynamic antagonism. Minor/Meaning Unknown.

Primidone lowers biotin levels through an unspecified interaction mechanism. Minor/Meaning Unknown. Biotin supplementation may be required.

Primidone decreases the level or effect of bosentan by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.Primidone decreases the level or effect of bosentan by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Brimonidine potentiates the effects of primidone through pharmacodynamic synergism. Minor/Meaning Unknown. Increased CNS depression.

brinzolamide, primidone. Mechanism: pharmacodynamic synergism. Minor/Meaning Unknown. Increased risk of anticonvulsant-induced osteomalacia.

Primidone lowers the level or effect of caffeine by affecting the metabolism of the liver enzyme CYP1A2. Minor/Meaning Unknown.

Primidone decreases the level or effect of celecoxib by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.

Primidone decreases the level or effect of cevimeline by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone lowers chloramphenicol levels by increasing metabolism. Minor/Meaning Unknown.

Primidone lowers chlorpromazine levels by increasing metabolism. Minor/Meaning Unknown.

Primidone decreases the level or effect of cimetidine by affecting the metabolism of the liver enzyme CYP2C19. Minor/Meaning Unknown.

Primidone decreases the effect of cisatracurium through pharmacodynamic antagonism. Minor/Meaning Unknown.

Primidone decreases the level or effect of clarithromycin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.Primidone decreases clarithromycin levels by increasing elimination. Minor/Meaning Unknown.

primidone, clomipramine. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

Primidone decreases clotrimazole levels by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.

Primidone decreases the level or effects of topical cocaine by affecting the metabolism of the liver enzyme CYP2B6. Minor/Meaning Unknown.

Primidone lowers cyanocobalamin levels by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.

Primidone decreases the level or effect of dapsone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

primidone, desipramine. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

Dexmethylphenidate enhances the effects of primidone by decreasing its metabolism. Minor/Meaning Unknown.

Primidone decreases the level or effect of diazepam by affecting the metabolism of the liver enzyme CYP2C19. Minor/Meaning Unknown.

Primidone decreases the level or effect of diclofenac by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.

Primidone decreases the level or effect of disopyramide by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of docetaxel by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of donepezil by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

primidone, dosulepin. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

Primidone, doxepin. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

Primidone decreases the level or effect of dutasteride by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of efavirenz by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of eplerenone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases erythromycin base levels by increasing elimination. Minor/Meaning Unknown.

Primidone decreases erythromycin ethyl succinate concentrations by increasing elimination. Minor/Meaning Unknown.

Primidone decreases erythromycin lactobionate levels by increasing elimination. Minor/Meaning Unknown.

Primidone decreases the concentration of erythromycin stearate by increasing its elimination. Minor/Meaning Unknown.

Ethosuximide decreases the effect of primidone through pharmacodynamic antagonism. Minor/Meaning Unknown.

Primidone decreases the level or effect of eucalyptus by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.Primidone and eucalyptus both increase sedation. Minor/Meaning Unknown.

Primidone decreases the level or effect of finasteride by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases fluconazole levels by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.

Primidone decreases the level or effect of flurbiprofen by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.

Primidone decreases the level or effect of fluvastatin by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.

Folic acid lowers primidone levels by increasing metabolism. Minor/Meaning Unknown.Primidone lowers folic acid levels by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.

Primidone decreases the level or effect of frovatriptan by affecting the metabolism of the liver enzyme CYP1A2. Minor/Meaning Unknown.

Primidone decreases the level or effect of galantamine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the levels or effects of green tea by increasing metabolism. Minor/Meaning Unknown. Green tea products may contain caffeine. The metabolism of xanthines like caffeine can be increased by taking barbiturates at the same time.

Primidone lowers griseofulvin levels by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.

haloperidol, primidone. Mechanism: pharmacodynamic synergism. Minor/Meaning Unknown. Risk of hyperthermia with haloperidol administration. in barbiturate withdrawal.

Primidone decreases the level or effect of ibuprofen by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.

Primidone decreases the level or effect of IV ibuprofen by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.

Primidone decreases the level or effect of imatinib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

primidone, imipramine. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

Primidone reduces the effect of incobotulinum toxin A through pharmacodynamic antagonism. Minor/Meaning Unknown.

Isocarboxazid increases primidone levels by decreasing metabolism. Minor/Meaning Unknown. theoretical interaction.

Primidone decreases the level or effect of isradipine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of itraconazole by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.Primidone decreases itraconazole levels by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.

Primidone decreases the level or effect of ketoconazole by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.Primidone decreases ketoconazole levels by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.

L-methylfolate lowers primidone levels by increasing metabolism. Minor/Meaning Unknown.Primidone enhances the effects of L-methylfolate by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.

Primidone decreases the level or effect of lansoprazole by affecting the metabolism of the liver enzyme CYP2C19. Minor/Meaning Unknown.

Primidone decreases levocarnitine levels through an unspecified mechanism of interaction. Minor/Meaning Unknown.

Primidone decreases the level or effect of levoketoconazole by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.Primidone decreases levoketoconazole levels by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.

Primidone lowers levothyroxine levels by increasing metabolism. Minor/Meaning Unknown.

Linezolid increases primidone levels by decreasing metabolism. Minor/Meaning Unknown. theoretical interaction.

Primidone lowers liothyronine levels by increasing metabolism. Minor/Meaning Unknown.

primidone, lofepramine. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

Primidone decreases the level or effect of losartan by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.

primidone, maprotiline. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

Primidone decreases the level or effect of meloxicam by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.

methazolamide, primidone. Mechanism: pharmacodynamic synergism. Minor/Meaning Unknown. Increased risk of anticonvulsant-induced osteomalacia.

Methsuximide decreases the effect of primidone through pharmacodynamic antagonism. Minor/Meaning Unknown.

Primidone decreases vaginal miconazole levels by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.

Primidone decreases the level or effect of montelukast by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Nettle enhances the effects of primidone through pharmacodynamic synergism. Minor/Meaning Unknown. (High dose nettle; theoretical interaction) May increase CNS depression.

Primidone decreases the level or effect of nimodipine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of nitrendipine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

primidone, nortriptyline. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

Primidone reduces the effect of onabotulinum toxin A through pharmacodynamic antagonism. Minor/Meaning Unknown.

Primidone decreases the level or effect of ondansetron by affecting the metabolism of the liver enzyme CYP1A2. Minor/Meaning Unknown.Primidone decreases the level or effect of ondansetron by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of oxybutynin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of paclitaxel by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the concentration or effect of paclitaxel-bound protein by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone reduces the effect of pancuronium through pharmacodynamic antagonism. Minor/Meaning Unknown.

Primidone decreases the level or effect of parecoxib by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Phenelzine increases primidone levels by decreasing metabolism. Minor/Meaning Unknown. theoretical interaction.

Primidone decreases the level or effect of pimozide by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of pioglitazone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of piroxicam by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.

Primidone decreases posaconazole levels by inhibiting GI absorption. Applies only to the oral form of both active ingredients. Minor/Meaning Unknown.

Procarbazine increases primidone levels by decreasing metabolism. Minor/Meaning Unknown. theoretical interaction.

Primidone decreases the level or effect of propafenone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

primidone, protriptyline. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

Primidone decreases the level or effect of quinine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the concentration or effect of rabeprazole by affecting hepatic/intestinal CYP3A4 enzyme metabolism. Minor/Meaning Unknown.

Primidone decreases the level or effect of ramelteon by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.Primidone decreases the level or effect of ramelteon by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the effect of rapacuronium through pharmacodynamic antagonism. Minor/Meaning Unknown.

Rasagiline increases primidone levels by decreasing metabolism. Minor/Meaning Unknown. theoretical interaction.

Primidone decreases the level or effect of riluzole by affecting the metabolism of the liver enzyme CYP1A2. Minor/Meaning Unknown.

Primidone decreases the effect of rocuronium through pharmacodynamic antagonism. Minor/Meaning Unknown.

Primidone decreases the amount of rose hips by increasing elimination. Minor/Meaning Unknown.

Primidone and sage both increase sedation. Minor/Meaning Unknown.Sage reduces the effect of primidone through pharmacodynamic antagonism. Minor/Meaning Unknown. theoretical interaction; Some types of sage can cause convulsions.

Primidone decreases the level or effect of saxagliptin by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Selegiline transdermal increases primidone levels by decreasing metabolism. Minor/Meaning Unknown. theoretical interaction.

Serdex methylphenidate/dexmethylphenidate potentiates the effects of primidone by decreasing metabolism. Minor/Meaning Unknown.

Siberian ginseng enhances the effects of primidone through pharmacodynamic synergism. Minor/Meaning Unknown. May increase CNS depression.

Primidone decreases the effects of succinylcholine through pharmacodynamic antagonism. Minor/Meaning Unknown.

Primidone decreases the level or effect of sufentanil by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of sulfamethoxazole by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.

Thioridazine lowers primidone levels through an unspecified mechanism of interaction. Minor/Meaning Unknown.

Primidone reduces thyroid dehydration by increasing metabolism. Minor/Meaning Unknown.

Primidone lowers tibolone levels by increasing metabolism. Minor/Meaning Unknown. theoretical interaction.

Primidone decreases the level or effect of tolbutamide by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.

Primidone lowers topiramate levels by increasing metabolism. Minor/Meaning Unknown.

Tranylcypromine increases primidone levels by decreasing metabolism. Minor/Meaning Unknown. theoretical interaction.

primidone, trazodone. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

primidone, trimipramine. Other (see comment). Minor/Meaning Unknown. Comment: Barbiturates can increase side effects, including respiratory depression, produced by toxic doses of TCAs. At therapeutic doses of TCAs, barbiturates increase metabolism and decrease blood levels of TCAs.

Valproic acid enhances the effects of primidone by increasing metabolism. Minor/Meaning Unknown. Valproic acid enhances the conversion of primidone to phenobarbital.

Primidone decreases the effect of vecuronium through pharmacodynamic antagonism. Minor/Meaning Unknown.

Primidone decreases the level or effect of vinblastine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of vincristine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of vincristine liposomal by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of vinorelbine by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of voriconazole by affecting the metabolism of the liver enzyme CYP2C19. Minor/Meaning Unknown.Primidone decreases the level or effect of voriconazole by affecting the metabolism of the liver enzyme CYP2C9/10. Minor/Meaning Unknown.

Primidone decreases the level or effect of zaleplon by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of ziprasidone by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of zolpidem by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.

Primidone decreases the level or effect of zonisamide by affecting the metabolism of the hepatic/intestinal enzyme CYP3A4. Minor/Meaning Unknown.