Carbamazepine and Nifedipine interaction
Carbamazepine and Nifedipine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Nifedipine label · effective 2026-02-05
John’s Wort reduce the bioavailability and efficacy of nifedipine; therefore nifedipine should not be used in combination with strong CYP3A inducers such as rifampin (See CONTRAINDICATIONS ).
Alternative antihypertensive therapy should be considered in patients taking phenytoin, phenobarbital, and carbamazepine.
Antitubercular Drugs Rifampin: Strong CYP3A inducers, such as rifampin, rifapentin, and rifabutin reduce the bioavailability of nifedipine which may reduce the efficacy of nifedipine; therefore nifedipine should not be used in combination with strong CYP3A inducers such as rifampin (See CONTRAINDICATIONS ).
John’s Wort is an inducer of CYP3A and may decrease exposure to nifedipine.
Strong CYP3A Inducers Strong CYP3A inducers, such as rifampin, rifabutin, phenobarbital, phenytoin, carbamazepine, and St.
From the Carbamazepine (EQUETRO) label · effective 2025-08-19
…alprazolam, aprepitant, buprenorphone, bupropion, buspirone, citalopram, clobazam, clonazepam, clozapine, cyclosporin, delavirdine, desipramine, diazepam, dicumarol, dihydropyridine calcium channel blockers (e.g., felodipine), doxycycline, ethosuximide, everolimus, felbamate, glucocorticoids, haloperidol, imatinib, itraconazole, lamotrigine, levothyroxine, lorazepam,…
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Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.