Metoprolol and Diltiazem Interaction
Drug interaction information between Metoprolol and Diltiazem.
Metoprolol and Diltiazem have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Metoprolol and Diltiazem. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
Both of these medicines slow down your heart rate and the electrical signals that tell your heart when to beat. Taking them together can make your heart beat much slower than it should.
What To Do
Your doctor should monitor your heart rate and pulse closely while you are taking both medications. Tell your healthcare provider if you feel dizzy, weak, or faint.
FDA Label Information
( 7.3 ) Concomitant use of glycosides, clonidine, and diltiazem and verapamil with beta-blockers can increase the risk of bradycardia. 7.4 Negative Chronotropes Digitalis glycosides, clonidine, diltiazem and verapamil slow atrioventricular conduction and decrease heart rate.
Metoprolol Also Interacts With
- Theophylline major
- Clonidine moderate
- Verapamil moderate
- Fluoxetine minor
- Paroxetine minor
Diltiazem Also Interacts With
- Ezetimibe major
- Ezetimibe/Simvastatin major
- Simvastatin major
- Theophylline major
- Rifampin moderate
Frequently Asked Questions
Can I take Metoprolol and Diltiazem together?
This is a moderate interaction. Your doctor should monitor your heart rate and pulse closely while you are taking both medications. Tell your healthcare provider if you feel dizzy, weak, or faint.
How serious is the interaction between Metoprolol and Diltiazem?
This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.
Why do Metoprolol and Diltiazem interact?
Both of these medicines slow down your heart rate and the electrical signals that tell your heart when to beat. Taking them together can make your heart beat much slower than it should.
Understanding the Metoprolol and Diltiazem Interaction
FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Metoprolol belongs to the Beta-Blocker class and Diltiazem belongs to the Calcium Channel Blocker class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Both of these medicines slow down your heart rate and the electrical signals that tell your heart when to beat. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Metoprolol has 18 total documented interactions on file in this dataset, and Diltiazem has 46. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Your doctor should monitor your heart rate and pulse closely while you are taking both medications. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Metoprolol or Diltiazem based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.