Diltiazem and Voriconazole interaction
Diltiazem and Voriconazole: 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 Voriconazole label · effective 2026-06-02
Dihydropyridine Calcium Channel Blockers (CYP3A4 Inhibition) In Vitro Studies Demonstrated Potential for Voriconazole to Inhibit Metabolism (Increased Plasma Exposure) Frequent monitoring for adverse reactions and toxicity related to calcium channel blockers.
Adjustment of calcium channel blocker dosage may be needed.
Other HIV Protease Inhibitors (CYP3A4 Inhibition) In Vivo Studies Showed No Significant Effects of Indinavir on Voriconazole Exposure In Vitro Studies Demonstrated Potential for Inhibition of Voriconazole Metabolism (Increased Plasma Exposure) No dosage adjustment in the voriconazole dosage needed for concomitant administration with indinavir.
Prednisolone and other corticosteroids (CYP3A4 Inhibition) In Vivo Studies Showed No Significant Effects of voriconazole on Prednisolone Exposure Not Studied In Vitro or In Vivo for Other Corticosteroids, but Drug Exposure Likely to be Increased No dosage adjustment for prednisolone when concomitantly administered with voriconazole [see Clinical Pharmacology…
Other HIV Protease Inhibitors (CYP3A4 Inhibition) In Vivo Studies Showed No Significant Effects on Indinavir Exposure No dosage adjustment for indinavir when concomitantly administered with voriconazole.
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.