Diltiazem and Dronedarone interaction
Diltiazem and Dronedarone: 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 Diltiazem (DILTIAZEM HYDROCHLORIDE in SODIUM CHLORIDE) label · effective 2025-04-15
Effect of other drugs on Diltiazem Cytochrome P450 3A4 Inhibitors/ Inducers Diltiazem is a substrate of the cytochrome P450 3A4 enzyme and inhibitors/inducers may change the pharmacological effect of diltiazem Monitor.
From the Dronedarone (Multaq) label · effective 2026-01-27
• Calcium channel blockers (CCB): Initiate CCB with low dose and increase after ECG verification of tolerability.
Calcium Channel Blockers Calcium channel blockers with depressant effects on the sinus and AV nodes could potentiate dronedarone's effects on conduction.
Give a low dose of calcium channel blockers initially and increase only after ECG verification of good tolerability [see Drug Interactions (7.3) , Clinical Pharmacology (12.3) ] .
Effects of Other Drugs on Dronedarone Ketoconazole and Other Potent CYP3A Inhibitors Concomitant use of ketoconazole as well as other potent CYP3A inhibitors such as itraconazole, voriconazole, ritonavir, clarithromycin, and nefazodone is contraindicated because exposure to dronedarone is significantly increased [see Contraindications (4) , Clinical Pharmacology…
Calcium Channel Blockers Verapamil and diltiazem are moderate CYP3A inhibitors and increase dronedarone exposure.
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.