Primidone Dose in Adults

Risk Factor C (Monitor therapy)

Acetaminophen

Barbiturates may increase the metabolism of Acetaminophen. This may 1) diminish the effect of acetaminophen; and 2) increase the risk of liver damage.

Alcohol (Ethyl)

CNS Depressants may enhance the CNS depressant effect of Alcohol (Ethyl).

Alizapride

May enhance the CNS depressant effect of CNS Depressants.

Apalutamide

CYP3A4 Inducers (Strong) may decrease the serum concentration of Apalutamide.

Barbiturates

Primidone may enhance the adverse/toxic effect of Barbiturates. Primidone is converted to phenobarbital, and thus becomes additive with existing barbiturate therapy.

Bazedoxifene

Primidone may decrease the serum concentration of Bazedoxifene. This may lead to loss of efficacy or, if bazedoxifene is combined with estrogen therapy, an increased risk of endometrial hyperplasia.

Benperidol

CYP3A4 Inducers (Strong) may decrease the serum concentration of Benperidol.

Beta-Blockers

Barbiturates may decrease the serum concentration of Beta-Blockers. Exceptions: Atenolol; Levobunolol; Metipranolol; Nadolol.

Bictegravir

CYP3A4 Inducers (Strong) may decrease the serum concentration of Bictegravir. Management: Rifampin is specifically contraindicated, and the use of carbamazepine, phenytoin, or phenobarbital is not recommended when alternatives are acceptable

Blood Pressure Lowering Agents

Barbiturates may enhance the hypotensive effect of Blood Pressure Lowering Agents.

Brentuximab Vedotin

CYP3A4 Inducers (Strong) may decrease the serum concentration of Brentuximab Vedotin. Specifically, concentrations of the active monomethyl auristatin E (MMAE) component may be decreased.

Brexanolone

CNS Depressants may enhance the CNS depressant effect of Brexanolone.

Brimonidine (Topical)

May enhance the CNS depressant effect of CNS Depressants.

Bromopride

May enhance the CNS depressant effect of CNS Depressants.

Calcifediol

CYP3A4 Inducers (Strong) may decrease the serum concentration of Calcifediol.

Calcium Channel Blockers

Barbiturates may increase the metabolism of Calcium Channel Blockers. Management: Monitor for decreased therapeutic effects of calcium channel blockers with concomitant barbiturate therapy. Calcium channel blocker dose adjustments may be necessary. Nimodipine Canadian labeling contraindicates concomitant use with phenobarbital. Exceptions: Clevidipine.

Cannabidiol

CYP3A4 Inducers (Strong) may decrease the serum concentration of Cannabidiol.

Cannabidiol

May enhance the CNS depressant effect of CNS Depressants.

Cannabis

CYP3A4 Inducers (Strong) may decrease the serum concentration of Cannabis. More specifically, tetrahydrocannabinol and cannabidiol serum concentrations may be decreased.

Cannabis

May enhance the CNS depressant effect of CNS Depressants.

CarBAMazepine

CYP3A4 Inducers (Strong) may decrease the serum concentration of CarBAMazepine.

Carbonic Anhydrase Inhibitors

May enhance the adverse/toxic effect of Primidone. Specifically, osteomalacia and rickets. Carbonic Anhydrase Inhibitors may decrease the serum concentration of Primidone. Exceptions: Brinzolamide; Dorzolamide.

Chlorphenesin Carbamate

May enhance the adverse/toxic effect of CNS Depressants.

ChlorproPAMIDE

CYP3A4 Inducers (Strong) may decrease the serum concentration of ChlorproPAMIDE.

Clindamycin (Systemic)

CYP3A4 Inducers (Strong) may decrease the serum concentration of Clindamycin (Systemic). Refer to the specific clindamycin (systemic) - rifampin drug interaction monograph for information concerning that combination.

CNS Depressants

May enhance the adverse/toxic effect of other CNS Depressants.

Corticosteroids (Systemic)

CYP3A4 Inducers (Strong) may decrease the serum concentration of Corticosteroids (Systemic). Exceptions: Hydrocortisone (Systemic); PrednisoLONE (Systemic); PredniSONE.

Cosyntropin

May enhance the hepatotoxic effect of Primidone.

Dabigatran Etexilate

Primidone may decrease the serum concentration of Dabigatran Etexilate.

Dabrafenib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Dabrafenib.

Dexmethylphenidate

May increase serum concentrations of the active metabolite(s) of Primidone. Specifically, phenobarbital concentrations could become elevated. Dexmethylphenidate may increase the serum concentration of Primidone.

Diethylstilbestrol

CYP3A4 Inducers (Strong) may decrease the serum concentration of Diethylstilbestrol.

Dimethindene (Topical)

May enhance the CNS depressant effect of CNS Depressants.

Doxercalciferol

CYP3A4 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Doxercalciferol.

Doxylamine

May enhance the CNS depressant effect of CNS Depressants. Management: The manufacturer of Diclegis (doxylamine/pyridoxine), intended for use in pregnancy, specifically states that use with other CNS depressants is not recommended.

Dronabinol

CYP3A4 Inducers (Strong) may decrease the serum concentration of Dronabinol.

Dronabinol

May enhance the CNS depressant effect of CNS Depressants.

Elagolix

CYP3A4 Inducers (Strong) may decrease the serum concentration of Elagolix.

Esketamine

May enhance the CNS depressant effect of CNS Depressants.

Eslicarbazepine

Primidone may decrease the serum concentration of Eslicarbazepine. (based on studies with phenobarbital)

Estriol (Systemic)

CYP3A4 Inducers (Strong) may decrease the serum concentration of Estriol (Systemic).

Estriol (Topical)

CYP3A4 Inducers (Strong) may decrease the serum concentration of Estriol (Topical).

Etizolam

CYP3A4 Inducers (Strong) may decrease the serum concentration of Etizolam.

Evogliptin

CYP3A4 Inducers (Strong) may decrease the serum concentration of Evogliptin.

Folic Acid

May decrease the serum concentration of Primidone. Additionally, folic acid may decrease concentrations of active metabolites of primidone (e.g., phenobarbital).

Fosphenytoin

May increase the metabolism of Primidone. The ratio of primidone:phenobarbital is thus changed.

Gestrinone

Primidone may decrease the serum concentration of Gestrinone.

Glecaprevir and Pibrentasvir

CYP3A4 Inducers (Strong) may decrease the serum concentration of Glecaprevir and Pibrentasvir.

Griseofulvin

Barbiturates may decrease the serum concentration of Griseofulvin.

Hydrocortisone (Systemic)

CYP3A4 Inducers (Strong) may decrease the serum concentration of Hydrocortisone (Systemic).

Ifosfamide

CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Ifosfamide. CYP3A4 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Ifosfamide.

Kava Kava

May enhance the adverse/toxic effect of CNS Depressants.

Leucovorin Calcium-Levoleucovorin

May decrease the serum concentration of Primidone. Additionally, leucovorin/levoleucovorin may decrease concentrations of active metabolites of primidone (e.g., phenobarbital).

LevETIRAcetam

Primidone may decrease the serum concentration of LevETIRAcetam.

Levomefolate

May decrease serum concentrations of the active metabolite(s) of Primidone. Levomefolate may decrease the serum concentration of Primidone.

Levomethadone

Primidone may decrease the serum concentration of Levomethadone.

Lofexidine

May enhance the CNS depressant effect of CNS Depressants. Management: Drugs listed as exceptions to this monograph are discussed in further detail in separate drug interaction monographs.

Magnesium Sulfate

May enhance the CNS depressant effect of CNS Depressants.

Methadone

Primidone may decrease the serum concentration of Methadone.

Methylfolate

May decrease the serum concentration of Primidone.

Methylphenidate

May increase serum concentrations of the active metabolite(s) of Primidone. Specifically, phenobarbital concentrations could become elevated. Methylphenidate may increase the serum concentration of Primidone.

MetroNIDAZOLE (Systemic)

Primidone may decrease the serum concentration of MetroNIDAZOLE (Systemic).

MetyroSINE

CNS Depressants may enhance the sedative effect of MetyroSINE.

Minocycline

May enhance the CNS depressant effect of CNS Depressants.

Multivitamins/Minerals (with ADEK, Folate, Iron)

May decrease the serum concentration of Barbiturates.

Nabilone

May enhance the CNS depressant effect of CNS Depressants.

Nalmefene

Primidone may decrease the serum concentration of Nalmefene.

Orlistat

May decrease the serum concentration of Anticonvulsants.

Oxcarbazepine

CYP3A4 Inducers (Strong) may decrease the serum concentration of OXcarbazepine. Specifically, the concentrations of the 10-monohydroxy active metabolite of oxcarbazepine may be decreased.

Phenytoin

May increase the metabolism of Primidone. The ratio of primidone:phenobarbital is thus changed.

Piribedil

CNS Depressants may enhance the CNS depressant effect of Piribedil.

Polatuzumab Vedotin

CYP3A4 Inducers (Strong) may decrease the serum concentration of Polatuzumab Vedotin. Exposure to unconjugated MMAE, the cytotoxic small molecule component of polatuzumab vedotin, may be decreased.

Pramipexole

CNS Depressants may enhance the sedative effect of Pramipexole.

PrednisoLONE (Systemic)

CYP3A4 Inducers (Strong) may decrease the serum concentration of PrednisoLONE (Systemic).

PredniSONE

CYP3A4 Inducers (Strong) may decrease the serum concentration of PredniSONE.

Propacetamol

Barbiturates may increase the metabolism of Propacetamol. This may 1) diminish the desired effects of propacetamol; and 2) increase the risk of liver damage.

Propafenone

CYP3A4 Inducers (Strong) may decrease the serum concentration of Propafenone.

Pyridoxine

May increase the metabolism of Barbiturates. Apparent in high pyridoxine doses (eg, 200 mg/day)

QuiNIDine

Primidone may decrease the serum concentration of QuiNIDine.

Ramelteon

CYP3A4 Inducers (Strong) may decrease the serum concentration of Ramelteon.

Reboxetine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Reboxetine.

Rifamycin Derivatives

May increase the metabolism of Barbiturates.

ROPINIRole

CNS Depressants may enhance the sedative effect of ROPINIRole.

Rotigotine

CNS Depressants may enhance the sedative effect of Rotigotine.

Rufinamide

Primidone may decrease the serum concentration of Rufinamide.

Ruxolitinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Ruxolitinib.

SAXagliptin

CYP3A4 Inducers (Strong) may decrease the serum concentration of SAXagliptin.

Selective Serotonin Reuptake Inhibitors

CNS Depressants may enhance the adverse/toxic effect of Selective Serotonin Reuptake Inhibitors. Specifically, the risk of psychomotor impairment may be enhanced.

Sertraline

CYP3A4 Inducers (Strong) may decrease the serum concentration of Sertraline.

Sulthiame

Primidone may enhance the adverse/toxic effect of Sulthiame.

Tetrahydrocannabinol

CYP3A4 Inducers (Strong) may decrease the serum concentration of Tetrahydrocannabinol.

Tetrahydrocannabinol

May enhance the CNS depressant effect of CNS Depressants.

Tetrahydrocannabinol and Cannabidiol

May enhance the CNS depressant effect of CNS Depressants.

Tetrahydrocannabinol and Cannabidiol

CYP3A4 Inducers (Strong) may decrease the serum concentration of Tetrahydrocannabinol and Cannabidiol.

Theophylline Derivatives

Barbiturates may decrease the serum concentration of Theophylline Derivatives. Exceptions: Dyphylline.

Thiazide and Thiazide-Like Diuretics

Barbiturates may enhance the orthostatic hypotensive effect of Thiazide and Thiazide-Like Diuretics.

Thiothixene

Primidone may decrease the serum concentration of Thiothixene.

Trimeprazine

May enhance the CNS depressant effect of CNS Depressants.

Tropisetron

CYP3A4 Inducers (Strong) may decrease the serum concentration of Tropisetron.

Udenafil

CYP3A4 Inducers (Strong) may decrease the serum concentration of Udenafil.

Valproate Products

May decrease the metabolism of Primidone. More specifically, the metabolism of phenobarbital, primidone's primary active metabolite, may be decreased. Primidone may increase the serum concentration of Valproate Products.

Zuclopenthixol

CYP3A4 Inducers (Strong) may decrease the serum concentration of Zuclopenthixol.

Risk Factor D (Consider therapy modification)

Abiraterone Acetate

CYP3A4 Inducers (Strong) may decrease the serum concentration of Abiraterone Acetate. Management: Avoid whenever possible. If such a combination cannot be avoided, increase abiraterone acetate dosing frequency from once daily to twice daily during concomitant use.

Acalabrutinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Acalabrutinib. Management: Avoid co-administration of strong CYP3A inducers in patients taking acalabrutinib. If strong CYP3A inducers cannot be avoided, increase the dose of acalabrutinib to 200 mg twice daily.

Afatinib

Primidone may decrease the serum concentration of Afatinib. Management: Per US labeling: if requiring chronic use of primidone, increase afatinib dose by 10 mg as tolerated; reduce to original afatinib dose 2-3 days after stopping primidonel. Per Canadian labeling: avoid combination if possible.

ARIPiprazole

CYP3A4 Inducers (Strong) may decrease the serum concentration of ARIPiprazole. Management: Double the oral aripiprazole dose and closely monitor. Reduce oral aripiprazole dose to 10-15 mg/day (for adults) if the inducer is discontinued. Avoid use of strong CYP3A4 inducers for more than 14 days with extended-release injectable aripiprazole.

ARIPiprazole Lauroxil

CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of ARIPiprazole Lauroxil. Management: Patients taking the 441 mg dose of aripiprazole lauroxil increase their dose to 662 mg if used with a strong CYP3A4 inducer for more than 14 days. No dose adjustment is necessary for patients using the higher doses of aripiprazole lauroxil.

Benzhydrocodone

Primidone may enhance the CNS depressant effect of Benzhydrocodone. Primidone may decrease serum concentrations of the active metabolite(s) of Benzhydrocodone. Specifically, serum concentrations of hydrocodone may be decreased. Management: Avoid use of benzhydrocodone and primidonel when possible. Monitor for respiratory depression/sedation. Because primidone is also a strong CYP3A4 inducer, monitor for decreased benzhydrocodone efficacy and withdrawal if combined.

Blonanserin

CNS Depressants may enhance the CNS depressant effect of Blonanserin.

Brexpiprazole

CYP3A4 Inducers (Strong) may decrease the serum concentration of Brexpiprazole. Management: If brexpiprazole is used together with a strong CYP3A4 inducer, the brexpiprazole dose should gradually be doubled over the course of 1 to 2 weeks.

Buprenorphine

Primidone may enhance the CNS depressant effect of Buprenorphine. Primidone may decrease the serum concentration of Buprenorphine. Management: Avoid use of buprenorphine and primidone when possible. Monitor for respiratory depression/sedation. Because primidone is also a strong CYP3A4 inducer, monitor for decreased buprenorphine efficacy and withdrawal if combined.

BusPIRone

CYP3A4 Inducers (Strong) may decrease the serum concentration of BusPIRone. Management: Consider alternatives to this combination. If coadministration of these agents is deemed necessary, monitor patients for reduced buspirone effects and increase buspirone doses as needed.

Cabozantinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Cabozantinib. Management: Avoid use of strong CYP3A4 inducers with cabozantinib if possible. If combined, cabozantinib dose adjustments are recommended and vary based on the cabozantinib product used and the indication for use. See monograph for details.

Canagliflozin

Primidone may decrease the serum concentration of Canagliflozin. Management: Consider increasing canagliflozin dose to 300 mg/day in patients with estimated GFR >60 mL/min/1.73 m2 who tolerate canagliflozin 100 mg/day and require greater glycemic control. Consider alternatives in patients with estimated GFR 45-60 mL/min/1.73 m2.

Chloramphenicol (Systemic)

May decrease the metabolism of Barbiturates. Barbiturates may increase the metabolism of Chloramphenicol (Systemic).

Chlormethiazole

May enhance the CNS depressant effect of CNS Depressants. Management: Monitor closely for evidence of excessive CNS depression. The chlormethiazole labeling states that an appropriately reduced dose should be used if such a combination must be used.

Clarithromycin

CYP3A4 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Clarithromycin. Clarithromycin may increase the serum concentration of CYP3A4 Inducers (Strong). CYP3A4 Inducers (Strong) may decrease the serum concentration of Clarithromycin. Management: Consider alternative antimicrobial therapy for patients receiving a CYP3A inducer. Drugs that enhance the metabolism of clarithromycin into 14hydroxyclarithromycin may alter the clinical activity of clarithromycin and may impair clarithromycin efficacy.

Codeine

Primidone may enhance the CNS depressant effect of Codeine. Primidone may decrease the serum concentration of Codeine. Management: Avoid use of codeine and primidone when possible. Monitor for respiratory depression/sedation. Because primidone is also a strong CYP3A4 inducer, monitor for decreased codeine efficacy and withdrawal if combined.

CycloSPORINE (Systemic)

Barbiturates may increase the metabolism of CycloSPORINE (Systemic).

CYP3A4 Substrates (High risk with Inducers)

CYP3A4 Inducers (Strong) may increase the metabolism of CYP3A4 Substrates (High risk with Inducers). Management: Consider an alternative for one of the interacting drugs. Some combinations may be specifically contraindicated. Consult appropriate manufacturer labeling. Exceptions: Benzhydrocodone; Buprenorphine; CarBAMazepine; Etizolam; HYDROcodone; TraMADol; Zolpidem.

Dasatinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Dasatinib. Management: Avoid when possible. If such a combination cannot be avoided, consider increasing dasatinib dose and monitor clinical response and toxicity closely.

Dexamethasone (Systemic)

CYP3A4 Inducers (Strong) may decrease the serum concentration of Dexamethasone (Systemic). Management: Consider dexamethasone dose increases in patients receiving strong CYP3A4 inducers and monitor closely for reduced steroid efficacy.

DOXOrubicin (Conventional)

CYP3A4 Inducers (Strong) may decrease the serum concentration of DOXOrubicin (Conventional). Management: Seek alternatives to strong CYP3A4 inducers in patients treated with doxorubicin. One U.S. manufacturer (Pfizer Inc.) recommends that these combinations be avoided.

Droperidol

May enhance the CNS depressant effect of CNS Depressants. Management: Consider dose reductions of droperidol or of other CNS agents (eg, opioids, barbiturates) with concomitant use. Exceptions to this monograph are discussed in further detail in separate drug interaction monographs.

Enzalutamide

CYP3A4 Inducers (Strong) may decrease the serum concentration of Enzalutamide. Management: Consider using an alternative agent that has no or minimal CYP3A4 induction potential when possible. If this combination cannot be avoided, increase the dose of enzalutamide from 160 mg daily to 240 mg daily.

Eravacycline

CYP3A4 Inducers (Strong) may decrease the serum concentration of Eravacycline. Management: Increase the eravacycline dose to 1.5 mg/kg every 12 hours when combined with strong CYP3A4 inducers.

Erlotinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Erlotinib. Management: Avoid combination if possible. If combination must be used, increase erlotinib dose by 50 mg increments every 2 weeks as tolerated, to a maximum of 450 mg/day.

Estrogen Derivatives (Contraceptive)

Barbiturates may diminish the therapeutic effect of Estrogen Derivatives (Contraceptive). Contraceptive failure is possible. Management: Use of a non-hormonal contraceptive is recommended.

Etoposide

CYP3A4 Inducers (Strong) may decrease the serum concentration of Etoposide. Management: When possible, seek alternatives to strong CYP3A4-inducing medications in patients receiving etoposide. If combined, monitor patients closely for diminished etoposide response and need for etoposide dose increases.

Etoposide Phosphate

CYP3A4 Inducers (Strong) may decrease the serum concentration of Etoposide Phosphate. Management: When possible, seek alternatives to strong CYP3A4inducing medications in patients receiving etoposide phosphate. If these combinations cannot be avoided, monitor patients closely for diminished etoposide phosphate response.

Everolimus

CYP3A4 Inducers (Strong) may decrease the serum concentration of Everolimus. Management: Avoid concurrent use of strong CYP3A4 inducers if possible. If coadministration cannot be avoided, double the daily dose of everolimus using increments of 5 mg or less. Monitor everolimus serum concentrations closely when indicated.

Exemestane

CYP3A4 Inducers (Strong) may decrease the serum concentration of Exemestane. Management: Exemestane U.S. product labeling recommends using an increased dose (50 mg/day) in patients receiving concurrent strong CYP3A4 inducers. The Canadian product labeling does not recommend a dose adjustment with concurrent use of strong CYP3A4 inducers.

Felbamate

May increase serum concentrations of the active metabolite(s) of Primidone. Specifically, phenobarbital concentrations may increase. Primidone may decrease the serum concentration of Felbamate. Management: In patients receiving primidone, initiate felbamate at 1200 mg/day in divided doses 3-4 times daily and reduce primidone dose by 20%. Monitor for increased phenobarbital concentrations/effects and decreased felbamate concentrations/effects.

FentaNYL

Primidone may enhance the CNS depressant effect of FentaNYL. Primidone may decrease the serum concentration of FentaNYL. Management: Avoid use of fentanyl and primidone when possible. Monitor for respiratory depression/sedation. Because primidone is also a strong CYP3A4 inducer, monitor for decreased fentanyl efficacy and withdrawal if combined.

Flunitrazepam

CNS Depressants may enhance the CNS depressant effect of Flunitrazepam.

Gefitinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Gefitinib. Management: In the absence of severe adverse reactions, increase gefitinib dose to 500 mg daily in patients receiving strong CYP3A4 inducers; resume 250 mg dose 7 days after discontinuation of the strong inducer. Carefully monitor clinical response.

GuanFACINE

CYP3A4 Inducers (Strong) may decrease the serum concentration of GuanFACINE. Management: Increase the guanfacine dose by up to double when initiating guanfacine in a patient taking a strong CYP3A4 inducer. Increase guanfacine dose gradually over 1 to 2 weeks if initiating strong CYP3A4 inducer therapy in a patient already taking guanfacine.

HYDROcodone

Primidone may enhance the CNS depressant effect of HYDROcodone. Primidone may decrease the serum concentration of HYDROcodone. Management: Avoid use of hydrocodone and primidone when possible. Monitor for respiratory depression/sedation. Because primidone is also a strong CYP3A4 inducer, monitor for decreased hydrocodone efficacy and withdrawal if combined.

HydrOXYzine

May enhance the CNS depressant effect of Barbiturates. Management: Consider a decrease in the barbiturate dose, as appropriate, when used together with hydroxyzine. With concurrent use, monitor patients closely for excessive response to the combination.

Imatinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Imatinib. Management: Avoid concurrent use of imatinib with strong CYP3A4 inducers when possible. If such a combination must be used, increase imatinib dose by at least 50% and monitor the patient's clinical response closely.

Ixabepilone

CYP3A4 Inducers (Strong) may decrease the serum concentration of Ixabepilone. Management: Avoid this combination whenever possible. If this combination must be used, a gradual increase in ixabepilone dose from 40 mg/m to 60 mg/m (given as a 4-hour infusion), as tolerated, should be considered.

LamoTRIgine

Primidone may decrease the serum concentration of LamoTRIgine. Management: Adjust dose per lamotrigine prescribing information guidelines during primidone treatment. Monitor for decreased concentration/effect if primidone is initiated/dose increased or increased concentration/effect if primidone is discontinued/dose decreased.

Larotrectinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Larotrectinib. Management: Avoid use of strong CYP3A4 inducers with larotrectinib. If this combination cannot be avoided, double the larotrectinib dose. Reduced to previous dose after stopping the inducer after a period of 3 to 5 times the inducer half-life.

Lefamulin

CYP3A4 Inducers (Strong) may decrease the serum concentration of Lefamulin. Management: Avoid concomitant use of lefamulin with strong CYP3A4 inducers unless the benefits outweigh the risks.

Lefamulin (Intravenous)

CYP3A4 Inducers (Strong) may decrease the serum concentration of Lefamulin (Intravenous). Management: Avoid concomitant use of lefamulin intravenous infusion with strong CYP3A4 inducers unless the benefits outweigh the risks.

LinaGLIPtin

CYP3A4 Inducers (Strong) may decrease the serum concentration of LinaGLIPtin. Management: Strongly consider using an alternative to any strong CYP3A4 inducer in patients who are being treated with linagliptin. If this combination is used, monitor patients closely for evidence of reduced linagliptin effectiveness.

Manidipine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Manidipine. Management: Consider avoiding concomitant use of manidipine and strong CYP3A4 inducers. If combined, monitor closely for decreased manidipine effects and loss of efficacy. Increased manidipine doses may be required.

Maraviroc

CYP3A4 Inducers (Strong) may decrease the serum concentration of Maraviroc. Management: Increase maraviroc adult dose to 600 mg twice daily when used with strong CYP3A4 inducers. This does not apply to patients also receiving strong CYP3A4 inhibitors. Do not use maraviroc with strong CYP3A4 inducers in patients with CrCl less than 30 mL/min.

Mefloquine

May diminish the therapeutic effect of Anticonvulsants. Mefloquine may decrease the serum concentration of Anticonvulsants. Management: Mefloquine is contraindicated for malaria prophylaxis in persons with a history of convulsions. Monitor anticonvulsant concentrations and treatment response closely with concurrent use.

Meperidine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Meperidine. Management: Consider increasing meperidine dose if concomitant use with strong CYP3A4 inducers is required. Monitor for signs and symptoms of opioid withdrawal.

Methotrimeprazine

CNS Depressants may enhance the CNS depressant effect of Methotrimeprazine. Methotrimeprazine may enhance the CNS depressant effect of CNS Depressants. Management: Reduce adult dose of CNS depressant agents by 50% with initiation of concomitant methotrimeprazine therapy. Further CNS depressant dosage adjustments should be initiated only after clinically effective methotrimeprazine dose is established.

MethylPREDNISolone

CYP3A4 Inducers (Strong) may decrease the serum concentration of MethylPREDNISolone. Management: Consider methylprednisolone dose increases in patients receiving strong CYP3A4 inducers and monitor closely for reduced steroid efficacy.

Mirodenafil

CYP3A4 Inducers (Strong) may decrease the serum concentration of Mirodenafil. Management: Consider avoiding the concomitant use of mirodenafil and strong CYP3A4 inducers. If combined, monitor for decreased mirodenafil effects. Mirodenafil dose increases may be required to achieve desired effects.

Opioid Agonists

CNS Depressants may enhance the CNS depressant effect of Opioid Agonists. Management: Avoid concomitant use of opioid agonists and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug.

Osimertinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Osimertinib.

OxyCODONE

Primidone may enhance the CNS depressant effect of OxyCODONE. Primidone may decrease the serum concentration of OxyCODONE. Management: Avoid use of oxycodone and primidone when possible. Monitor for respiratory depression/sedation. Because primidone is also a strong CYP3A4 inducer, monitor for decreased oxycodone efficacy and withdrawal if combined.

Perampanel

CYP3A4 Inducers (Strong) may decrease the serum concentration of Perampanel. Management: Increase the perampanel starting dose to 4 mg/day when perampanel is used concurrently with moderate and strong CYP3A4 inducers.

Perampanel

May enhance the CNS depressant effect of CNS Depressants. Management: Patients taking perampanel with any other drug that has CNS depressant activities should avoid complex and high-risk activities, particularly those such as driving that require alertness and coordination, until they have experience using the combination.

Pitolisant

CYP3A4 Inducers (Strong) may decrease the serum concentration of Pitolisant. Management: For patients who are stable on pitolisant doses of 8.9 mg or 17.8 mg/day and who are also taking a strong CYP3A4 inducer, increase the pitolisant dose over 7 days to double the original dose (ie, to either 17.8 mg/day or 35.6 mg/day, respectively).

Progestins (Contraceptive)

Primidone may diminish the therapeutic effect of Progestins (Contraceptive). Contraceptive failure is possible. Management: Use of alternative, nonhormonal contraceptives is recommended.

QUEtiapine

CYP3A4 Inducers (Strong) may decrease the serum concentration of QUEtiapine. Management: An increase in quetiapine dose (as much as 5 times the regular dose) may be required to maintain therapeutic benefit. Reduce the quetiapine dose back to the previous/regular dose within 7-14 days of discontinuing the inducer.

Radotinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Radotinib. Management: Consider alternatives to this combination when possible as the risk of radotinib treatment failure may be increased.

RisperiDONE

CYP3A4 Inducers (Strong) may decrease the serum concentration of RisperiDONE. Management: Consider increasing the dose of oral risperidone (to no more than double the original dose) if a strong CYP3A4 inducer is initiated. For patients on IM risperidone, consider an increased IM dose or supplemental doses of oral risperidone.

Rolapitant

CYP3A4 Inducers (Strong) may decrease the serum concentration of Rolapitant. Management: Avoid rolapitant use in patients requiring chronic administration of strong CYP3A4 inducers. Monitor for reduced rolapitant response and the need for alternative or additional antiemetic therapy even with shorter-term use of such inducers.

Sirolimus

CYP3A4 Inducers (Strong) may decrease the serum concentration of Sirolimus. Management: Avoid concomitant use of strong CYP3A4 inducers and sirolimus if possible. If combined, monitor for reduced serum sirolimus concentrations. Sirolimus dose increases will likely be necessary to prevent subtherapeutic sirolimus levels.

Sodium Oxybate

May enhance the CNS depressant effect of CNS Depressants. Management: Consider alternatives to combined use. When combined use is needed, consider minimizing doses of one or more drugs. Use of sodium oxybate with alcohol or sedative hypnotics is contraindicated.

SUFentanil

Primidone may enhance the CNS depressant effect of SUFentanil. Primidone may decrease the serum concentration of SUFentanil. Management: Avoid use of sufentanil and primidone when possible. Monitor for respiratory depression/sedation. Because primidone is also a strong CYP3A4 inducer, monitor for decreased sufentanil efficacy and withdrawal if combined.

SUNItinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of SUNItinib. Management: Avoid when possible. If such a combination cannot be avoided, sunitinib dose increases are recommended, and vary by indication. See full monograph for details.

Suvorexant

CNS Depressants may enhance the CNS depressant effect of Suvorexant. Management: Dose reduction of suvorexant and/or any other CNS depressant may be necessary. Use of suvorexant with alcohol is not recommended, and the use of suvorexant with any other drug to treat insomnia is not recommended.

Tadalafil

CYP3A4 Inducers (Strong) may decrease the serum concentration of Tadalafil. Management: Erectile dysfunction: monitor for decreased effectiveness - no standard dose adjustments recommended. Avoid use of tadalafil for pulmonary arterial hypertension in patients receiving a strong CYP3A4 inducer.

Tamoxifen

CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Tamoxifen. CYP3A4 Inducers (Strong) may decrease the serum concentration of Tamoxifen. Management: Consider alternatives to concomitant use of strong CYP3A4 inducers and tamoxifen. If the combination cannot be avoided, monitor for reduced therapeutic effects of tamoxifen.

Tapentadol

May enhance the CNS depressant effect of CNS Depressants. Management: Avoid concomitant use of tapentadol and benzodiazepines or other CNS depressants when possible. These agents should only be combined if alternative treatment options are inadequate. If combined, limit the dosages and duration of each drug.

Temsirolimus

CYP3A4 Inducers (Strong) may decrease the serum concentration of Temsirolimus. Management: Consider increasing the dose of temsirolimus to 50 mg IV/week (from 25 mg IV/week) if a concomitant CYP3A4 strong inducer is necessary.

Teniposide

Barbiturates may decrease the serum concentration of Teniposide. Management: Consider alternatives to combined treatment with barbiturates and teniposide due to the potential for decreased teniposide concentrations. If the combination cannot be avoided, monitor teniposide response closely.

Thiotepa

CYP3A4 Inducers (Strong) may increase serum concentrations of the active metabolite(s) of Thiotepa. CYP3A4 Inducers (Strong) may decrease the serum concentration of Thiotepa. Management: Thiotepa prescribing information recommends avoiding concomitant use of thiotepa and strong CYP3A4 inducers. If concomitant use is unavoidable, monitor for adverse effects.

TiaGABine

CYP3A4 Inducers (Strong) may decrease the serum concentration of TiaGABine. Management: Approximately 2-fold higher tiagabine doses and a more rapid dose titration will likely be required in patients concomitantly taking a strong CYP3A4 inducer.

TraMADol

Primidone may enhance the CNS depressant effect of TraMADol. Primidone may decrease the serum concentration of TraMADol. Management: Avoid use of tramadol and primidone when possible. Monitor for respiratory depression/sedation. Because primidone is also a strong CYP3A4 inducer, monitor for decreased tramadol efficacy and withdrawal if combined.

Tricyclic Antidepressants

Barbiturates may increase the metabolism of Tricyclic Antidepressants.

Vemurafenib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Vemurafenib. Management: Avoid concurrent use of vemurafenib with a strong CYP3A4 inducer and replace with another agent when possible. If a strong CYP3A4 inducer is indicated and unavoidable, the dose of vemurafenib may be increased by 240 mg (1 tablet) as tolerated.

Vilazodone

CYP3A4 Inducers (Strong) may decrease the serum concentration of Vilazodone. Management: Consider increasing vilazodone dose by as much as 2-fold (do not exceed 80 mg/day), based on response, in patients receiving strong CYP3A4 inducers for > 14 days. Reduce to the original vilazodone dose over 1-2 weeks after inducer discontinuation.

Vitamin K Antagonists (eg, warfarin)

Barbiturates may increase the metabolism of Vitamin K Antagonists. Management: Monitor INR more closely. An anticoagulant dose increase may be needed after a barbiturate is initiated or given at an increased dose. Anticoagulant dose decreases may be needed following barbiturate discontinuation or dose reduction.

Vortioxetine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Vortioxetine. Management: Consider increasing the vortioxetine dose to no more than 3 times the original dose when used with a strong drug metabolism inducer for more than 14 days. The vortioxetine dose should be returned to normal within 14 days of stopping the strong inducer.

Zaleplon

CYP3A4 Inducers (Strong) may decrease the serum concentration of Zaleplon. Management: Consider the use of an alternative hypnotic that is not metabolized by CYP3A4 in patients receiving strong CYP3A4 inducers. If zalephon is combined with a strong CYP3A4 inducer, monitor for decreased effectiveness of zaleplon.

Zolpidem

CNS Depressants may enhance the CNS depressant effect of Zolpidem. Management: Reduce the Intermezzo brand sublingual zolpidem adult dose to 1.75 mg for men who are also receiving other CNS depressants. No such dose change is recommended for women. Avoid use with other CNS depressants at bedtime; avoid use with alcohol.

Risk Factor X (Avoid combination)

Abemaciclib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Abemaciclib.

Alpelisib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Alpelisib.

Antihepaciviral Combination Products

CYP3A4 Inducers (Strong) may decrease the serum concentration of Antihepaciviral Combination Products.

Apixaban

CYP3A4 Inducers (Strong) may decrease the serum concentration of Apixaban.

Apremilast

CYP3A4 Inducers (Strong) may decrease the serum concentration of Apremilast.

Aprepitant

CYP3A4 Inducers (Strong) may decrease the serum concentration of Aprepitant.

Artemether

CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Artemether. Specifically, dihydroartemisinin concentrations may be reduced. CYP3A4 Inducers (Strong) may decrease the serum concentration of Artemether.

Asunaprevir

CYP3A4 Inducers (Strong) may decrease the serum concentration of Asunaprevir.

Axitinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Axitinib.

Azelastine (Nasal)

CNS Depressants may enhance the CNS depressant effect of Azelastine (Nasal).

Bedaquiline

CYP3A4 Inducers (Strong) may decrease the serum concentration of Bedaquiline.

Bortezomib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Bortezomib.

Bosutinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Bosutinib.

Brigatinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Brigatinib.

Bromperidol

May enhance the CNS depressant effect of CNS Depressants.

Cariprazine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Cariprazine.

Ceritinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Ceritinib.

CloZAPine

CYP3A4 Inducers (Strong) may decrease the serum concentration of CloZAPine.

Cobicistat

Primidone may decrease the serum concentration of Cobicistat.

Cobimetinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Cobimetinib.

Copanlisib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Copanlisib.

Crizotinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Crizotinib.

Daclatasvir

CYP3A4 Inducers (Strong) may decrease the serum concentration of Daclatasvir.

Dasabuvir

CYP3A4 Inducers (Strong) may decrease the serum concentration of Dasabuvir.

Deflazacort

CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Deflazacort.

Delamanid

CYP3A4 Inducers (Strong) may decrease the serum concentration of Delamanid.

Dienogest

CYP3A4 Inducers (Strong) may decrease the serum concentration of Dienogest. Management: Avoid use of dienogest for contraception when using medications that induce CYP3A4 and for at least 28 days after discontinuation of a CYP3A4 inducer. An alternative form of contraception should be used during this time.

Dolutegravir

Primidone may decrease the serum concentration of Dolutegravir. Specifically, the Primidone metabolite phenobarbital may decrease Dolutegravir serum concentrations.

Doravirine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Doravirine.

Doxycycline

Barbiturates may decrease the serum concentration of Doxycycline.

Dronedarone

CYP3A4 Inducers (Strong) may decrease the serum concentration of Dronedarone.

Duvelisib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Duvelisib.

Elbasvir

Elbasvir's serum levels may drop when CYP3A4 Inducers (Strong) are taken.

Eliglustat

CYP3A4 Inducers (Strong) may decrease the serum concentration of Eliglustat.

Encorafenib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Encorafenib.

Entrectinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Entrectinib.

Erdafitinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Erdafitinib.

Etravirine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Etravirine.

Fedratinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Fedratinib.

Flibanserin

CYP3A4 Inducers (Strong) may decrease the serum concentration of Flibanserin.

Fosaprepitant

CYP3A4 Inducers (Strong) may decrease the serum concentration of Fosaprepitant. Specifically, CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite aprepitant.

Fosnetupitant

CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Fosnetupitant.

Fostamatinib

CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Fostamatinib.

Gemigliptin

CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Gemigliptin. CYP3A4 Inducers (Strong) may decrease the serum concentration of Gemigliptin.

Glasdegib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Glasdegib.

Grazoprevir

CYP3A4 Inducers (Strong) may decrease the serum concentration of Grazoprevir.

Hemin

Barbiturates may diminish the therapeutic effect of Hemin.

Ibrutinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Ibrutinib.

Idelalisib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Idelalisib.

Irinotecan Products

CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Irinotecan Products. Specifically, serum concentrations of SN-38 may be reduced. CYP3A4 Inducers (Strong) may decrease the serum concentration of Irinotecan Products.

Isavuconazonium Sulfate

CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Isavuconazonium Sulfate. Specifically, CYP3A4 Inducers (Strong) may decrease isavuconazole serum concentrations.

Itraconazole

CYP3A4 Inducers (Strong) may decrease the serum concentration of Itraconazole.

Ivabradine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Ivabradine.

Ivacaftor

CYP3A4 Inducers (Strong) may decrease the serum concentration of Ivacaftor.

Ivosidenib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Ivosidenib.

Ixazomib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Ixazomib.

Lapatinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Lapatinib. Management: If therapy overlap cannot be avoided, consider titrating lapatinib gradually from 1,250 mg/day up to 4,500 mg/day (HER2 positive metastatic breast cancer) or 1,500 mg/day up to 5,500 mg/day (hormone receptor/HER2 positive breast cancer) as tolerated.

Ledipasvir

Primidone may decrease the serum concentration of Ledipasvir.

Lorlatinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Lorlatinib.

Lumefantrine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Lumefantrine.

Lurasidone

CYP3A4 Inducers (Strong) may decrease the serum concentration of Lurasidone.

Macimorelin

CYP3A4 Inducers (Strong) may decrease the serum concentration of Macimorelin.

Macitentan

CYP3A4 Inducers (Strong) may decrease the serum concentration of Macitentan.

Methoxyflurane

Barbiturates may enhance the nephrotoxic effect of Methoxyflurane. Barbiturates may increase the metabolism of Methoxyflurane.

Methoxyflurane

CYP2A6 Inducers may enhance the nephrotoxic effect of Methoxyflurane. CYP2A6 Inducers may increase the metabolism of Methoxyflurane.

Mianserin

May enhance the CNS depressant effect of Barbiturates. Mianserin may diminish the therapeutic effect of Barbiturates. Barbiturates may decrease the serum concentration of Mianserin.

Midostaurin

CYP3A4 Inducers (Strong) may decrease the serum concentration of Midostaurin.

MiFEPRIStone

CYP3A4 Inducers (Strong) may decrease the serum concentration of MiFEPRIStone.

Naldemedine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Naldemedine.

Naloxegol

CYP3A4 Inducers (Strong) may decrease the serum concentration of Naloxegol.

Neratinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Neratinib.

Netupitant

CYP3A4 Inducers (Strong) may decrease the serum concentration of Netupitant.

NIFEdipine

CYP3A4 Inducers (Strong) may decrease the serum concentration of NIFEdipine.

Nilotinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Nilotinib.

NiMODipine

CYP3A4 Inducers (Strong) may decrease the serum concentration of NiMODipine.

Nisoldipine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Nisoldipine.

Olaparib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Olaparib.

Orphenadrine

CNS Depressants may enhance the CNS depressant effect of Orphenadrine.

Oxomemazine

May enhance the CNS depressant effect of CNS Depressants.

Palbociclib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Palbociclib.

Panobinostat

CYP3A4 Inducers (Strong) may decrease the serum concentration of Panobinostat.

Paraldehyde

CNS Depressants may enhance the CNS depressant effect of Paraldehyde.

PAZOPanib

CYP3A4 Inducers (Strong) may decrease the serum concentration of PAZOPanib.

Pexidartinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Pexidartinib.

Pimavanserin

CYP3A4 Inducers (Strong) may decrease the serum concentration of Pimavanserin.

Piperaquine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Piperaquine.

PONATinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of PONATinib.

Praziquantel

CYP3A4 Inducers (Strong) may decrease the serum concentration of Praziquantel. Management: Use of praziquantel with strong CYP3A4 inducers is contraindicated. Discontinue rifampin 4 weeks prior to initiation of praziquantel therapy. Rifampin may be resumed the day following praziquantel completion.

Pretomanid

CYP3A4 Inducers (Strong) may decrease the serum concentration of Pretomanid.

Ranolazine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Ranolazine.

Regorafenib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Regorafenib.

Ribociclib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Ribociclib.

Rilpivirine

Primidone may decrease the serum concentration of Rilpivirine.

Rivaroxaban

CYP3A4 Inducers (Strong) may decrease the serum concentration of Rivaroxaban.

Roflumilast

CYP3A4 Inducers (Strong) may decrease the serum concentration of Roflumilast. Management: Roflumilast U.S. prescribing information recommends against combining strong CYP3A4 inducers with roflumilast. The Canadian product monograph makes no such recommendation but notes that such agents may reduce roflumilast therapeutic effects.

RomiDEPsin

CYP3A4 Inducers (Strong) may decrease the serum concentration of RomiDEPsin.

Simeprevir

CYP3A4 Inducers (Strong) may decrease the serum concentration of Simeprevir.

Sofosbuvir

Primidone may decrease the serum concentration of Sofosbuvir.

Somatostatin Acetate

May enhance the adverse/toxic effect of Barbiturates. Specifically, Somatostatin Acetate may enhance or prolong Barbiturate effects, including sedative effects.

Sonidegib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Sonidegib.

SORAfenib

CYP3A4 Inducers (Strong) may decrease the serum concentration of SORAfenib.

Tasimelteon

CYP3A4 Inducers (Strong) may decrease the serum concentration of Tasimelteon.

Tenofovir Alafenamide

Primidone may decrease the serum concentration of Tenofovir Alafenamide.

Thalidomide

CNS Depressants may enhance the CNS depressant effect of Thalidomide.

Ticagrelor

CYP3A4 Inducers (Strong) may decrease serum concentrations of the active metabolite(s) of Ticagrelor. CYP3A4 Inducers (Strong) may decrease the serum concentration of Ticagrelor.

Tofacitinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Tofacitinib.

Tolvaptan

CYP3A4 Inducers (Strong) may decrease the serum concentration of Tolvaptan. Management: If concurrent use is necessary, increased doses of tolvaptan (with close monitoring for toxicity and clinical response) may be needed.

Toremifene

CYP3A4 Inducers (Strong) may decrease the serum concentration of Toremifene.

Trabectedin

CYP3A4 Inducers (Strong) may decrease the serum concentration of Trabectedin.

Ulipristal

CYP3A4 Inducers (Strong) may decrease the serum concentration of Ulipristal.

Ulipristal

Barbiturates may decrease the serum concentration of Ulipristal.

Upadacitinib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Upadacitinib.

Valbenazine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Valbenazine.

Vandetanib

CYP3A4 Inducers (Strong) may decrease the serum concentration of Vandetanib.

Velpatasvir

CYP3A4 Inducers (Strong) may decrease the serum concentration of Velpatasvir.

Venetoclax

CYP3A4 Inducers (Strong) may decrease the serum concentration of Venetoclax.

VinCRIStine (Liposomal)

CYP3A4 Inducers (Strong) may decrease the serum concentration of VinCRIStine (Liposomal).

Vinflunine

CYP3A4 Inducers (Strong) may decrease the serum concentration of Vinflunine.

Vorapaxar

CYP3A4 Inducers (Strong) may decrease the serum concentration of Vorapaxar.

Voriconazole

Barbiturates may decrease the serum concentration of Voriconazole.

Voxilaprevir

CYP3A4 Inducers (Strong) may decrease the serum concentration of Voxilaprevir.