Buspirone and Diltiazem interaction
Buspirone and Diltiazem: both prescribing labels describe 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 Buspirone (Buspirone Hydrochloride) label · effective 2026-03-18
This finding is consistent with the in vivo interactions observed between buspirone and the following: Diltiazem and verapamil: In a study of nine healthy volunteers, coadministration of buspirone (10 mg as a single dose) with verapamil (80 mg t.i.d.) or diltiazem (60 mg t.i.d.) increased plasma buspirone concentrations (verapamil increased AUC and C max of buspirone…
Other inhibitors and inducers of CYP3A4: Substances that inhibit CYP3A4, such as ketoconazole or ritonavir, may inhibit buspirone metabolism and increase plasma concentrations of buspirone while substances that induce CYP3A4, such as dexamethasone or certain anticonvulsants (phenytoin, phenobarbital, carbamazepine), may increase the rate of buspirone metabolism.
Consequently, when administered with a potent inhibitor of CYP3A4, a low dose of buspirone used cautiously is recommended.
Adverse events attributable to buspirone may be more likely during concomitant administration with either diltiazem or verapamil.
From the Diltiazem (DILTIAZEM HYDROCHLORIDE in SODIUM CHLORIDE) label · effective 2025-04-15
Buspirone Carbamazepine Cyclosporine Quinidine Ranolazine Limit ranolazine to 500 mg twice daily.
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.