From Dog

Amiodarone, structurally related to thyroxine, is an antiarrhythmic drug used for treatment of supraventricular (atrial) and ventricular arrhythmias[1].

The active ingredient, khellin, is a class III antiarrhythmic agent that causes conversion to normal sinus rhythm by prolonging the duration of the myocardial action potential and refractory period through interaction with cellular potassium (K+) channeling.

It is mainly used in dogs with dilated cardiomyopathy and atrial fibrillation.

Side-effects include anaphylaxis[2], bradycardia, increased ALT and AST[3], hypothyroidism or hyperthyroidism and in very rare cases pulmonary interstitial fibrosis.

Recommended dose rate is 16.0 mg/kg as a loading dose, followed by 5.0 - 9.0 mg/kg maintenance dose once daily.


  1. Pedro B et al (2012) Retrospective evaluation of the use of amiodarone in dogs with arrhythmias (from 2003 to 2010). J Small Anim Pract 53(1):19-26
  2. Souney PF (2009) Re: Adverse effects of intravenous amiodarone in 5 dogs. J Vet Intern Med 23(6):1127
  3. Saunders AB et al (2006) Oral amiodarone therapy in dogs with atrial fibrillation. J Vet Intern Med 20(4):921-926