Amiodarone pharmacokinetics.

The single-dose pharmacokinetics of amiodarone have been studied in volunteer subjects given 400 mg doses by the intravenous and oral routes. The data show the compound to have a very large volume of distribution, a low total clearance, and a long and variable terminal elimination half-life. In patients the terminal elimination half-life was on the order of 40 days, with a more rapid phase of elimination in the first few days following the withdrawal of therapy. The terminal elimination half-life of desethylamiodarone was longer than that of the parent compound. High concentrations of amiodarone and its desethyl metabolite were found in tissue samples, with fat forming a potentially large tissue reservoir of the drug.