Effect of renal failure or biliary stasis on the pharmacokinetics of amiodarone in the rat.
The single dose intravenous pharmacokinetics of amiodarone (50 mg/kg) were examined in rats with 72 h of biliary stasis secondary to bile duct ligation compared with paired control animals; and in rats with uranyl nitrate induced acute renal failure compared with paired control animals. Plasma and tissue levels (liver, kidney, heart, and lung) of amiodarone (1) and its N-deethyl metabolite 2 were obtained at 4 and 24 h following drug administration. Pharmacokinetic parameters were derived from plasma samples obtained over a 24-h period. Compared with controls, biliary stasis caused a decrease in the total clearance of 1 (1.74 versus 0.35 L/h/kg) and in the volume of distribution at steady state (21.1 versus 5.0 L/kg); renal failure caused a decrease in total clearance (1.67 versus 0.9 L/h/kg) and an increase in apparent elimination half-life (13.7 versus 10.1 h). Both disease processes produced significantly higher plasma levels of 1 when compared with control animals at 4 and 24 h. However, only the cholestatic animals had consistently higher tissue levels of 1 in the face of elevated plasma levels. In normal rats, no 1 or 2 was detected in the urine after a 50 mg/kg intravenous dose of 1, and less than 0.5% of the total dose of amiodarone (1) was excreted into bile by 12 h.
D000638:Amiodarone / Q000378:metabolism*; D000818:Animals; D001572:Benzofurans / Q000378:metabolism*; D002779:Cholestasis / Q000378:metabolism*; D003640:Dealkylation; D005965:Glucuronates / Q000378:metabolism; D007676:Kidney Failure, Chronic / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013997:Time Factors; D014018:Tissue Distribution
D001572:Benzofurans; D005965:Glucuronates; D000638:Amiodarone