Verapamil and Zafirlukast interaction
Verapamil and Zafirlukast: the Zafirlukast 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 Zafirlukast label · effective 2026-03-16
As zafirlukast is known to be an inhibitor of CYP3A4 in vitro , it is reasonable to employ appropriate clinical monitoring when these drugs are coadministered with zafirlukast.
Coadministration of zafirlukast with itraconazole, a strong CYP3A4 inhibitor, caused no change in plasma levels of zafirlukast.
No other formal drug-drug interaction studies between zafirlukast and marketed drugs known to be metabolized by the P450 3A4 (CYP3A4) isoenzyme (e.g., dihydropyridine calcium-channel blockers, cyclosporin, cisapride) have been conducted.
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.