Clonidine and Diltiazem Interaction
Drug interaction information between Clonidine and Diltiazem.
Clonidine and Diltiazem have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Clonidine 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 medicines slow down the heart, and taking them together can make the heart beat too slowly.
What To Do
Your doctor should check your heart rate often to make sure it does not drop to a dangerous level.
FDA Label Information
Sinus bradycardia resulting in hospitalization and pacemaker insertion has been reported in association with the use of clonidine concomitantly with diltiazem or verapamil.
Clonidine Also Interacts With
- Carvedilol moderate
- Metoprolol moderate
- Repaglinide moderate
- Sotalol moderate
- Amitriptyline minor
Diltiazem Also Interacts With
- Ezetimibe major
- Ezetimibe/Simvastatin major
- Simvastatin major
- Theophylline major
- Rifampin moderate
Frequently Asked Questions
Can I take Clonidine and Diltiazem together?
This is a minor interaction. Your doctor should check your heart rate often to make sure it does not drop to a dangerous level.
How serious is the interaction between Clonidine and Diltiazem?
This interaction is classified as "minor" severity by the FDA. Minor interactions are unlikely to cause significant problems but should still be mentioned to your healthcare provider.
Why do Clonidine and Diltiazem interact?
Both medicines slow down the heart, and taking them together can make the heart beat too slowly.
Understanding the Clonidine and Diltiazem Interaction
FDA-approved prescribing information for these two drugs flags their combination as a minor-severity interaction. Clonidine belongs to the Central Alpha-2 Agonist 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 medicines slow down the heart, and taking them together can make the heart beat too slowly. 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. Clonidine has 29 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 check your heart rate often to make sure it does not drop to a dangerous level. 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 Clonidine 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.