Amiodarone is a class III antiarrhythmic agent approved for the treatment of life-threatening ventricular tachyarrhythmias. Because of potential toxicity the serum level of this drug should be monitored. Its major elimination is by hepatic excretion. Negligible renal excretion occurs. Use of the drug is restricted because of its many side effects, including pulmonary fibrosis, neuromuscular weakness, exacerbation of congestive heart failure, tremor, thyroid dysfunction, and interaction with other drugs. Potassium or magnesium deficiency should be corrected. AST and ALT should be monitored.