Nifedipine and Phenobarbital, hyoscyamine, atropine, and scopolamine interaction
Nifedipine and Phenobarbital, hyoscyamine, atropine, and scopolamine: the Nifedipine prescribing label describes an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Nifedipine label · effective 2026-02-05
Alternative antihypertensive therapy should be considered in patients taking phenytoin, phenobarbital, and carbamazepine.
Strong CYP3A Inducers Strong CYP3A inducers, such as rifampin, rifabutin, phenobarbital, phenytoin, carbamazepine, and St.
Phenytoin, Phenobarbital, and Carbamazepine: Nifedipine is metabolized by CYP3A.
Phenobarbital and carbamazepine are also inducers of CYP3A.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
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.