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Dofetilide and Clarithromycin Interaction

Drug interaction information between Dofetilide and Clarithromycin.

Dofetilide and Clarithromycin have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Dofetilide and Clarithromycin. 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.

Drug A

Dofetilide

Class III Antiarrhythmic

Drug B

Clarithromycin

Macrolide Antibiotic

How They Interact

Clarithromycin affects how this heart medicine is broken down, which can increase the risk of a life-threatening irregular heartbeat.

What To Do

This combination is not recommended and should be avoided to prevent serious heart complications.

FDA Label Information

Clinically Significant Drug Interactions with Clarithromycin Tablets Drugs That Are Affected By Clarithromycin Tablets Drug(s) with Pharmacokinetics Affected by Clarithromycin Tablets Recommendation Comments Antiarrhythmics: Disopyramide Quinidine Dofetilide Amiodarone Sotalol Procainamide Not Recommended Disopyramide, Quinidine: There have been postmarketing reports of torsades de pointes occurring with concurrent use of clarithromycin and quinidine or disopyramide.

Frequently Asked Questions

Can I take Dofetilide and Clarithromycin together?

This is a moderate interaction. This combination is not recommended and should be avoided to prevent serious heart complications.

How serious is the interaction between Dofetilide and Clarithromycin?

This interaction is classified as "moderate" severity by the FDA. Moderate interactions may worsen your condition or change how your medications work.

Why do Dofetilide and Clarithromycin interact?

Clarithromycin affects how this heart medicine is broken down, which can increase the risk of a life-threatening irregular heartbeat.

Understanding the Dofetilide and Clarithromycin Interaction

FDA-approved prescribing information for these two drugs flags their combination as a moderate-severity interaction. Dofetilide belongs to the Class III Antiarrhythmic class and Clarithromycin belongs to the Macrolide Antibiotic class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Clarithromycin affects how this heart medicine is broken down, which can increase the risk of a life-threatening irregular heartbeat. 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. Dofetilide has 8 total documented interactions on file in this dataset, and Clarithromycin has 81. 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: This combination is not recommended and should be avoided to prevent serious heart complications. 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 Dofetilide or Clarithromycin 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.