[Acceleration of amiodarone elimination by cholestyramine]

In eleven patients serum levels of amiodarone and its desethyl metabolite were determined after a single dose of 400 mg amiodarone given with and without subsequent administration of colestyramine. In addition, the elimination half-life was measured in three patients after discontinuation of long-term amiodarone therapy. Mean serum levels of amiodarone at 7 1/2 hours after dosing (n = 11) were 0.42 +/- 0.11 micrograms/ml without colestyramine and 0.21 +/- 0.14 micrograms/ml with colestyramine (P less than 0.01). Elimination half-life after discontinuing long-term amiodarone therapy (n = 3) was 23 1/2, 29 and 32 days, respectively (half-life in eight controls: 35-58 days). The results indicate that colestyramine significantly reduces the enterohepatic circulation of amiodarone. Therefore, colestyramine should be capable of accelerating the regression of dose-dependent side-effects of amiodarone by enhancing its elimination.