Does Diltiazem Interact With Propranolol?

Administration of diltiazem hydrochloride concomitantly with propranolol in five normal volunteers resulted in increased propranolol levels in all subjects and bioavailability of propranolol was increased approximately 50%.

Severity: Minor

Severity basis: drug interactions section. Combining Diltiazem (Calcium channel blocker) and Propranolol (Beta-blocker) is classified as a minor interaction.

What to Do

This is generally a minor interaction, but review it with your pharmacist to be sure it is safe for you.

From the FDA Label

Administration of diltiazem hydrochloride concomitantly with propranolol in five normal volunteers resulted in increased propranolol levels in all subjects and bioavailability of propranolol was increased approximately 50%.

Source: FDA structured product labeling (set_id 0089fc7a-a7aa-4873-b699-39a1b21616ca).

Diltiazem

Calcium channel blocker

Brands: Cardizem, Cartia XT, Tiazac

View Diltiazem safety profile

Propranolol

Beta-blocker

Brands: Inderal

View Propranolol safety profile

Check these against your full medication list in our free Interaction Checker

This information is educational — not medical advice.

This page is provided for general educational purposes and summarizes publicly available data from sources such as the U.S. Food & Drug Administration. It is not a substitute for the judgment of a licensed clinician and should not be used to start, stop, or change any medication. It may be incomplete or out of date, and individual circumstances vary. Always talk with your prescriber or pharmacist about your specific medications and health conditions. If you think you may have a medical emergency, call 911.

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