Diltiazem and Digoxin Interaction
Drug interaction information between Diltiazem and Digoxin.
Diltiazem and Digoxin have a documented moderate interaction in FDA labeling.
FDA drug labeling documents a moderate-severity interaction between Diltiazem and Digoxin. 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
Diltiazem can cause the amount of digoxin in your blood to rise, which may lead to side effects from having too much medicine in your system.
What To Do
Your doctor should check your digoxin blood levels whenever you start, stop, or change your dose of diltiazem.
FDA Label Information
Digitalis : Administration of diltiazem hydrochloride with digoxin in 24 healthy male subjects increased plasma digoxin concentrations approximately 20%. Another investigator found no increase in digoxin levels in 12 patients with coronary artery disease. Monitor digoxin levels when initiating, adjusting, and discontinuing diltiazem hydrochloride therapy to avoid possible over- or under- digitalization (see WARNINGS ).
Diltiazem Also Interacts With
- Ezetimibe major
- Ezetimibe/Simvastatin major
- Simvastatin major
- Theophylline major
- Rifampin moderate
Digoxin Also Interacts With
- Nicardipine major
- Posaconazole major
- Sotalol moderate
- Dofetilide moderate
- Ivabradine moderate
Frequently Asked Questions
Can I take Diltiazem and Digoxin together?
This is a moderate interaction. Your doctor should check your digoxin blood levels whenever you start, stop, or change your dose of diltiazem.
How serious is the interaction between Diltiazem and Digoxin?
This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.
Why do Diltiazem and Digoxin interact?
Diltiazem can cause the amount of digoxin in your blood to rise, which may lead to side effects from having too much medicine in your system.
Understanding the Diltiazem and Digoxin Interaction
FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Diltiazem belongs to the Calcium Channel Blocker class and Digoxin belongs to the Cardiac Glycoside class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Diltiazem can cause the amount of digoxin in your blood to rise, which may lead to side effects from having too much medicine in your system. 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. Diltiazem has 46 total documented interactions on file in this dataset, and Digoxin has 120. 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 digoxin blood levels whenever you start, stop, or change your dose of diltiazem. 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 Diltiazem or Digoxin 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.