Amiodarone

Amiodarone (Cordarone, Pacerone) is an anti-arrhythmic agent used for the treatment and prophylaxis of ventricular fibrillation and ventricular tachycardia1. Although the exact mechanism of action is unknown (come on, scientists), Amiodarone slows conduction of the cardiac action potential by altering potassium channels1, 2. Although not indicated for this purpose, it is an effective medication for controlling atrial fibrillation and is used intravenously to convert to a normal sinus rhythm1, 2.

Despite its effectiveness, Amiodarone is often reserved for those who have not responded to safer drugs. Amiodarone is highly lipid soluble, accumulating in many tissues including the liver and lungs2. Its half-life is approximately 58 days, so it continues to act, or cause adverse effects, for weeks after dosing has stopped1, 2.

grapefuit-warning

Amiodarone is metabolized by the enzyme CYP3A4 in the liver. Remember that grapefruit juice (who drinks this anyway?) inhibits this enzyme and will increase Amiodarone levels!

Lung damage– pneumonitis, pulmonary fibrosis, pleural effusion– is the greatest concern and patient’s receiving long-term, high-dose therapy are at greater risk2, 3. Amiodarone is also cardiotoxic and may increase dysrhythmic activity causing sinus bradycardia or an AV block2. Liver toxicity is also a concern, so hepatic function tests and signs of liver injury– nausea, vomiting, jaundice, dark urine– should be monitored2. Intravenous Amiodarone may cause hypotension, bradycardia or AV block, and phlebitis2.

  1. https://www.drugbank.ca/drugs/DB01118
  2. Lehne, R. A. (2013). Pharmacology for Nursing Care, 8th Edition  Retrieved from https://pageburstls.elsevier.com/#/books/978-1-4377-3582-6/
  3. https://www.drugs.com/pro/amiodarone.html
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