Pharmacokinetics of amoxapine and its active metabolites.
The plasma concentrations of amoxapine and its active metabolites, 8-hydroxyamoxapine and 7-hydroxyamoxapine were determined in 8 healthy volunteers receiving a single oral dose of 100 mg of the drug. Considerable interindividual variation was seen in the plasma levels of the three substances. Amoxapine reached maximum levels of 67.4 +/- 35.8 ng/ml between 1 and 2 h after administration. The decline of amoxapine levels in plasma was biphasic. The mean elimination half-life was 9.8 +/- 2.6 h and the estimated first-pass loss ranged between 0.18 and 0.54. The peak levels of the metabolites were reached between 1 and 3 h after administration, with 8-hydroxyamoxapine levels significantly higher than those of 7-hydroxyamoxapine. The mean elimination half-lives were 30.8 and 5.1 h for 8-hydroxyamoxapine and 7-hydroxyamoxapine respectively. The margins of the plasma concentrations reached at steady-state were calculated according to pharmacokinetics parameters for a dosage interval of 8 h.
D000328:Adult; D000657:Amoxapine / Q000031:analogs & derivatives / Q000097:blood*; D002849:Chromatography, Gas; D003989:Dibenzoxazepines / Q000097:blood*; D005260:Female; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D013997:Time Factors
D003989:Dibenzoxazepines; C035234:8-hydroxyamoxapine; C041917:7-hydroxyamoxapine; D000657:Amoxapine