Drug Interaction Report

Dofetilide and Fingolimod: Interaction Details

A pharmacist-reviewed analysis of the Dofetilide and Fingolimod interaction: the documented clinical effects, severity rating, onset, mechanism, and management considerations, with cited references throughout.

AI-assisted, pharmacist-reviewed · Source data updated Aug 8, 2026 · Sources: FDA labeling, DDInter 2.0, cited literature

Dofetilide

Tikosyn Tikosyn®
+

Fingolimod

Gilenya Gilenya® Tascenso
Dr. Brian Staiger, PharmD, BCPS
Medically reviewed by
Dr. Brian Staiger, PharmD, BCPS
Updated Aug 8, 2026
Editorial policy · Data sources
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Interaction severity
Contraindicated
These should generally not be used together.
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.

Of 454 documented Dofetilide interactions, 33 are rated contraindicated — including this one.
Worried about symptoms right now? Contact your pharmacist or prescriber, or call Poison Control at 1-800-222-1222 (US). Call 911 for an emergency.
Onset
unspecified
Evidence
theoretical
Severity
Contraindicated

What happens

Increased risk of QT interval prolongation, bradycardia or heart block

Interaction Deep Dive

Dofetilide, a class III antiarrhythmic agent, has the potential to cause bradycardia, heart block, QT interval prolongation, and cardiac arrhythmias1. Concomitant use of dofetilide (a class III antiarrhythmic agent) with fingolimod is contraindicated due to the potential for bradycardia, heart block, additive QT interval prolongation, and an increased risk of torsade de pointes 2.

Why it happens (mechanism)

Additive QT interval prolongation; additive cardiac effects

Literature reports

1 report — tap to read

a) Bradycardia and atrioventricular block have occurred after the first dose of fingolimod; prolongation of the QT interval has also been reported. A patient receiving dofetilide who is initiated on fingolimod may have an increased risk of developing bradycardia, heart block, QT interval prolongation, and torsade de pointes due to additive cardiac effects 2.

Common questions

Can I take Dofetilide and Fingolimod together?

Increased risk of QT interval prolongation, bradycardia or heart block Always confirm with your pharmacist or prescriber before making any change.

How serious is the Dofetilide and Fingolimod interaction?

It is rated contraindicated. These should generally not be used together.

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.

From our Q&A

Real reader questions about these medications, each personally answered by our pharmacist:

Questions for your pharmacist

  • Does my dose of Dofetilide or Fingolimod 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 (2)

  1. Product Information: TIKOSYN(R) oral capsules, dofetilide oral capsules. Pfizer Labs (per manufacturer), New York, NY, 2011. DailyMed
  2. Product Information: GILENYA(TM) oral capsules, fingolimod oral capsules. Novartis Pharmaceuticals Corporation (Per Manufacturer), East Hanover, NJ, 2012. DailyMed
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Dofetilide

Keep reading about Dofetilide

All Dofetilide interactions (454) Dofetilide drug information
Also serious with: Bictegravir Cimetidine Saquinavir Cisapride
Fingolimod

Keep reading about Fingolimod

All Fingolimod interactions (74) Fingolimod drug information
Also serious with: Disopyramide Penbutolol Atenolol Loperamide
Beyond drug–drug

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:

Dofetilide + Activated Charcoal American Hellebore Arsenic Cesium Ephedra Grapefruit Sida Cordifolia St. John's Wort + 138 more
Fingolimod + Activated Charcoal Beer Siberian Cocklebur Wine Active Hexose Correlated Compound (ahcc) Alfalfa American Ginseng Andrographis + 98 more

major · moderate · minor — check everything you take with our drug–supplement interaction checker.

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This information is for education, not a substitute for professional medical advice. Do not start, stop, or change any medication without talking to your pharmacist or prescriber.