Dexamethasone and Diltiazem interaction
Dexamethasone and Diltiazem: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Dexamethasone (Hemady) label · effective 2026-01-09
• Avoid concomitant use of strong CYP3A4 inhibitors or inducers.
Avoid coadministration of strong CYP3A4 inhibitors or consider alternative medication that are not strong CYP3A4 inhibitors.
If concomitant use of strong CYP3A4 inhibitors cannot be avoided, closely monitor for adverse drug reactions.
( 7.2 ) 7.1 Effect of Other Drugs on HEMADY Strong CYP3A4 inhibitors Coadministration of strong and moderate CYP3A4 inhibitors increased dexamethasone exposure [see Clinical Pharmacology ( 12.3 )] , which may increase the risk of adverse reactions [see Warnings and Precautions ( 5 ) and Adverse Reactions ( 6 )] .
From the Diltiazem (DILTIAZEM HYDROCHLORIDE in SODIUM CHLORIDE) label · effective 2025-04-15
Coadministration of diltiazem with rifampin or any known CYP3A4 inducer should be avoided when possible, and alternative therapy considered [see Clinical Pharmacology (12.3)]. a Strong and moderate inhibitors increase the AUC of sensitive substrates of CYP3A4 by ≥ 5 and ≥ 2-fold, respectively b These examples are a guide and not considered a comprehensive list…
• CYP3A4 Inducers: Avoid concomitant use.
An adjustment in the diltiazem dose may be warranted CYP inducers Examples b : Rifampin, carbamazepine CYP3A inducers can lower the plasma levels of diltiazem.
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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.