Disopyramide and Telithromycin: Interaction Details
AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature
Telithromycin
No brand names on recordDisopyramide
How we grade severity & evidence
Severity levels
- Contraindicated: These should generally not be used together.
- Major: Potentially serious — often needs a change or close monitoring.
- Moderate: Can be significant — usually manageable with monitoring.
- Minor: Usually limited clinical impact.
Evidence grades
- Established: Well documented — supported by controlled studies or strong clinical data.
- Probable: Good supporting evidence, though not definitively proven.
- Suspected: Some evidence suggests this interaction, but it is not well established.
- Possible: Limited or conflicting evidence; the interaction may occur.
- Theoretical: Predicted from the drugs' pharmacology; not yet confirmed in people.
Ratings come from the documented interaction literature and are reviewed by a pharmacist. They describe the documented risk of the combination, not what will necessarily happen to you — your dose, timing, and health picture all matter.
What happens
An increased risk of cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest)
Interaction Deep Dive
Telithromycin may prolong the QT interval in some patients. Because Class IA antiarrhythmics may also prolong the QT interval and increase the risk of arrhythmias, the concurrent administration of telithromycin and a Class IA antiarrhythmic should be avoided13.
Why it happens (mechanism)
Additive effect on QT interval
Common questions
Can I take Disopyramide and Telithromycin together?
An increased risk of cardiotoxicity (QT prolongation, torsades de pointes, cardiac arrest) Always confirm with your pharmacist or prescriber before making any change.
How serious is the Disopyramide and Telithromycin interaction?
It is rated major. Potentially serious — often needs a change or close monitoring.
How quickly could this interaction happen?
The documented onset is "unspecified". The timing of this interaction is not well characterized.
How strong is the evidence for this interaction?
The evidence is graded "theoretical". Predicted from the drugs' pharmacology; not yet confirmed in people.
Questions for your pharmacist
- Does my dose of Disopyramide or Telithromycin need adjusting while I take them together?
- What symptoms should prompt me to call you or my prescriber right away?
- Does the timing of my doses matter for this combination?
- Is there a safer alternative to one of these medications for me?
References (3)
- Product Information: KETEK(R) oral tablets, telithromycin oral tablets. Sanofi-Aventis US,LLC, Bridgewater, NJ, 2007. DailyMed
- Product Information: NUEDEXTA(TM) oral capsules, dextromethorphan hydrobromide and quinidine sulfate oral capsules. Avanir Pharmaceuticals, Inc, Aliso Viejo, CA, 2010. DailyMed
- Product Information: PRONESTYL oral capsules, oral tablets, procainamide hcl oral capsules, oral tablets. Apothecon, Princeton, NJ, 2006.
Keep reading about Telithromycin
Keep reading about Disopyramide
These medications also interact with supplements
Prescription drugs aren't the whole picture — herbal and dietary supplements can interact with them too. From the evidence-graded Natural Medicines database:
major · moderate · minor — check everything you take with our drug–supplement interaction checker.
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