What is the prevalence and clinical presentation of amiodarone-related hepatic injury in patients receiving amiodarone?
Amiodarone therapy is associated with asymptomatic aminotransferase elevation in about 25% of patients and symptomatic hepatitis in 3%, necessitating careful risk-benefit assessment before discontinuation given the competing risk of sudden cardiac death.
The prevalence of apparent amiodarone-related hepatic injury in 104 patients followed prospectively is compared to that reported in the literature. Asymptomatic elevation of serum aminotransferase levels was detected in approximately one-fourth of the patients, a figure similar to the average of reported cases. The frequency of extrahepatic organ toxicity was increased in patients with elevated levels. Symptomatic "hepatitis" developed in 3% of this series and in less than 1% of cases in the literature. Evidence of hepatic phospholipidosis and the development of pseudoalcoholic liver injury is most likely due to the biochemical effects of the drug and to possible metabolic idiosyncrasy, respectively. Serial blood enzyme measurements, as recommended by the manufacturer, may offer some protection against the development of more serious liver injury. However, levels of amiodarone may persist in various tissues for weeks to months following withdrawal, and stopping the drug does not guarantee the prompt reversal of any organ toxicity. Accordingly, the risks posed and benefits offered by amiodarone should be carefully weighed prior to discontinuing the drug, as the risk of sudden cardiac death may outweigh the hazards of ongoing hepatic, pulmonary or other toxicity.
Lewis et al. (1989) studied this question.