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Tikosyn Side Effects

Generic Name: dofetilide

Note: This page contains side effects data for the generic drug dofetilide. It is possible that some of the dosage forms included below 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

As well as its needed effects, dofetilide (the active ingredient contained in Tikosyn) may cause unwanted side effects that require medical attention.

Major Side Effects

If any of the following side effects occur while taking dofetilide, check with your doctor immediately:

More common:
  • Dizziness
  • fainting
  • fast heartbeat
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

Minor Side Effects

Some dofetilide side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

Less common:
  • Abdominal or stomach pain
  • accidental injury
  • back pain
  • chills
  • cough
  • diarrhea
  • fever
  • flu-like symptoms
  • general feeling of discomfort or illness
  • headache
  • joint pain
  • loss of appetite
  • migraine
  • muscle aches and pains
  • nausea
  • rash
  • runny nose
  • shivering
  • sneezing
  • sore throat
  • sweating
  • trouble sleeping
  • vomiting

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

It is possible that some side effects of Tikosyn may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

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