Diltiazem and Labetalol interaction
Diltiazem and Labetalol: 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 Diltiazem (DILTIAZEM HYDROCHLORIDE in SODIUM CHLORIDE) label · effective 2025-04-15
• Concomitant administration with IV beta-blockers.
Beta-blockers Increased risk of bradycardia, AV block, and depression of contractility.
Beta-blocker may need to be decreased [see Warnings and Precautions (5.1, 5.2)].
• Beta-Blockers: Monitor for bradycardia, AV block, and depression of contractility.
From the Labetalol (Labetalol Hydrochloride) label · effective 2025-12-19
IV administration of non-dihydropyridine calcium-channel antagonists (e.g., verapamil) Hypersensitivity reactions, including anaphylaxis, to labetalol Bronchial asthma ( 4 )
Calcium Channel Blockers Coadministration of labetalol HCl with non-dihydropyrindine calcium-channel antagonists (e.g., verapamil) is contraindicated [see Contraindications (4) ].
Avoid the use of labetalol in patients receiving calcium-channel antagonists.
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.