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Tikosyn Side Effects

Generic Name: dofetilide

Note: This document contains side effect information about dofetilide. Some of the dosage forms listed on this page may not apply to the brand name Tikosyn.

In Summary

Common side effects of Tikosyn include: ventricular arrhythmia, ventricular tachycardia, and chest pain. Other side effects include: flu-like symptoms. See below for a comprehensive list of adverse effects.

For the Consumer

Applies to dofetilide: oral capsule

Along with its needed effects, dofetilide (the active ingredient contained in Tikosyn) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking dofetilide:

More common Less common
  • Chest pain
  • confusion
  • facial or flaccid paralysis
  • numbness or tingling of the hands, feet, or face
  • paralysis
  • pounding, slow heartbeat
  • slurred speech
  • swelling of the ankles, arms, face, feet, fingers, legs, lips, tongue, or throat
  • troubled breathing
  • unexplained shortness of breath
  • unusual tiredness or weakness
  • weight gain
  • yellow eyes or skin

Some side effects of dofetilide may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

Less common

For Healthcare Professionals

Applies to dofetilide: oral capsule


Torsade de pointes is the only arrhythmia reported by the manufacturer that showed a dose-response relationship.[Ref]

Cardiovascular effects have included ventricular arrhythmias, AV block, bundle branch block, heart block, chest pain, angioedema, bradycardia, cerebral ischemia, cerebrovascular accident, edema, heart arrest and myocardial infarct.[Ref]


General side effects including headache (11%), dizziness (8%), flu syndrome ( 4%), insomnia (4%), accidental injury (3%), back pain (3%) and rash (3%) and sudden death have been reported.[Ref]


Gastrointestinal effects have included nausea (5%), diarrhea (3%) and abdominal pain (3%).[Ref]


Respiratory effects have included respiratory tract infection (7%), dyspnea (6%) and cough.[Ref]

Nervous system

Nervous system effects have included paresthesias, facial paralysis, paralysis, flaccid paralysis, migraine and syncope.[Ref]


Hepatic side effects including liver damage has been reported with a frequency of less than 2%.[Ref]


1. "Product Information. Tikosyn (dofetilide)" Pfizer US Pharmaceuticals, Atlanta, GA.

2. Frost L, Mortensen PE, Tingleff J, Platou ES, Christiansen EH, Christiansen N "Efficacy and safety of dofetilide, a new class III antiarrhythmic agent, in acute termination of atrial fibrillation or flutter afte coronary artery bypass surgery. Dofetilide Post-CABG Study Group." Int J Cardiol 58 (1997): 135-40

3. Lenz TL, Hilleman DE "Dofetilide, a new class III antiarrhythmic agent." Pharmacotherapy 20 (2000): 776-86

4. Crijns HJ, Kingma JH, Gosselink AT, Dalrymple HW, De Langen CD, Lie K "Sequential bilateral bundle branch block during dofetilide, a new class III antiarrhythmic agent, in a patient with atria fibrillation." J Cardiovasc Electrophysiol 4 (1993): 459-66

Some side effects of Tikosyn may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

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