Phencyclidine disposition after intravenous and oral doses.
[3H]-Phencyclidine (PCP) hydrochloride was given in intravenous (0.1 or 1 mg) or oral (1 mg) doses to male subjects. After 1 mg IV, drug and metabolites were recovered in urine (72.8 +/- 4.0% of dose), feces (4.7 +/- 0.9%), and perspiration. Fecal excretion was low (3.4 +/- 0.4%) after oral dosing and oral bioavailability was estimated at 72%. PCP comprised 16% of urinary radioactivity with 31% consisting of enzymatically hydrolyzable conjugates of hydroxylated metabolites. Both cis and trans isomers of 4-phenyl-4-(1-piperidinyl)cyclohexanol were found. Maximum average plasma PCP concentrations of 2.7 to 2.9 ng/ml were observed after oral and intravenous 1-mg doses. Blood/plasma ratios were approximately 1.0 and plasma binding was about 65%. Parent drug was found in saliva. Apparent terminal phase half-lifes averaged 21 +/- 3 hr (harmonic mean 17 hr, range 7 to 46 hr). The volume of distribution averaged 6.2 +/- 0.3 l/kg. Renal clearances were variable, but the average was 9% of the total clearance. Thus, PCP is cleared principally by metabolism.
D000284:Administration, Oral; D000328:Adult; D001798:Blood Proteins / Q000378:metabolism; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007275:Injections, Intravenous; D007700:Kinetics; D008297:Male; D010622:Phencyclidine / Q000008:administration & dosage / Q000378:metabolism*; D011485:Protein Binding; D012463:Saliva / Q000378:metabolism
D001798:Blood Proteins; D010622:Phencyclidine