Pharmacokinetics of chlorzoxazone in humans.
Twenty-three normal male subjects received 900 mg of acetaminophen and 750 mg of chlorzoxazone as an oral suspension. Analysis of plasma samples indicated a rapid absorption and rapid elimination of chlorzoxazone. Average values of the elimination half-life and plasma clearance were 1.12 +/- 0.48 hr and 148.0 +/- 39.9 ml/min, respectively. Analysis of urine samples showed that chlorzoxazone was eliminated from the body as the glucuronide conjugate of the intermediate metabolite 6-hydroxychlorzoxazone, to the extent of 74% of the dose. The plasma and the urinary excretion data were fitted to theoretical equations, and excellent fits were obtained using a five-parameter pharmacokinetic model.
D000082:Acetaminophen / Q000378:metabolism; D000328:Adult; D001583:Benzoxazoles / Q000378:metabolism*; D001711:Biotransformation; D002753:Chlorzoxazone / Q000031:analogs & derivatives / Q000378:metabolism* / Q000652:urine; D004338:Drug Combinations; D006207:Half-Life; D006801:Humans; D007700:Kinetics; D008297:Male; D008954:Models, Biological
D001583:Benzoxazoles; D004338:Drug Combinations; C039289:6-hydroxychlorzoxazone; D000082:Acetaminophen; D002753:Chlorzoxazone