title: Tissue extraction of amiodarone and N-desethylamiodarone in man after a single oral dose.
abstract: The hepatic extraction of amiodarone and N-desethylamiodarone has been investigated in seven patients following catheterization of the portal and hepatic veins under general anaesthesia. Amiodarone (600 mg) was administered orally 4 h before regional blood sampling. Concentrations of amiodarone and N-desethylamiodarone, determined by h.p.l.c., were about twice as high in the portal vein compared with those in the hepatic vein, the calculated hepatic extraction ratios of both compounds being 0.39 +/- 0.07 and 0.34 +/- 0.03, respectively. The presence of N-desethylamiodarone in the portal vein in higher concentrations than in the hepatic vein strongly suggests that N-dealkylation of amiodarone occurs in the gut wall or lumen, a finding which might account for the low and highly variable intersubject amiodarone bioavailability.
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000638:Amiodarone / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000378:metabolism*; D001572:Benzofurans / Q000378:metabolism*; D005260:Female; D006801:Humans; D008099:Liver / Q000378:metabolism*; D008297:Male
chemical_list: D001572:Benzofurans; C036116:desethylamiodarone; D000638:Amiodarone