Long-term efficacy and toxicity of high- and low-dose amiodarone regimens

Amiodarone is an effective antiarrhythmic drug for the control of potentially lethal and lethal ventricular arrhythmias (VA). In the United States, a high-dose regimen has been used at the expense of a high toxicity profile for the control of lethal VAs. Significant antiarrhythmic efficacy has also been established with low-dose regimens, which carry a low rate of intolerable side effects (5.4%) when compared with the high-dose regimen (16.7%). The high incidence of tolerable and intolerable adverse side effects is probably related to high amiodarone loading (31.92 g) and maintenance doses (520 mg/d). In contrast, the low-dose regimen uses much lower loading (7.2 g) and maintenance (280 mg/d) doses.