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Phencyclidine and phenylcyclohexene disposition after smoking phencyclidine
Author(s) -
Edgar Cook C,
Brine D R,
Quin G D,
PerezReyes Mario,
Di Guiseppi Stephanie R
Publication year - 1982
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1038/clpt.1982.88
Subject(s) - phencyclidine , chemistry , urine , chromatography , pharmacology , pharmacokinetics , medicine , biochemistry , nmda receptor , receptor
Five men who smoked parsley cigarettes containing 100 μg of [ 3 H]‐phencyclidine hydrochloride (PCP · HCl) inhaled 69 ± 5(SEM) % of the total radioactivity in the cigarette. Both PCP and its pyrolysis product, 1 ‐phenylcyclohexene (PC), were found and measured in plasma. Calculations based on the assumption that the ratio of these two products was the same as in simulated smoking studies and based on either area under the curve or urinary excretion of PCP indicated that most of the PCP in smoke was absorbed. Mean half‐life (t½) of PCP (24 ± 7 hr, harmonic mean 18 hr) and ratios of metabolites in plasma and urine were close to those previously reported after intravenous and oral doses. A second peak in PCP plasma concentrations was observed, possibly due to slow efflux from the lungs. PC plasma concentrations (maximum 0.35 ± 0.06 pmol/ml) were lower than those of PCP (maximum 0.62 ± 0.09 pmol/ml) and its mean t½ (14 ± 3 hr, harmonic mean 12 hr) was shorter than that of PCP. Only traces of PC were found in urine. Only small amounts of metabolites from PC were found nonconjugated in plasma (to about 0.1 pmol/ml) or urine (<2% of radioactivity), but larger quantities were found as enzyme‐hydrolyzable conjugates in urine (6% of radioactivity). Conjugates were also found in plasma (to about 0.12 pmollml). Clinical Pharmacology and Therapeutics (1982) 31, 635–641; doi: 10.1038/clpt.1982.88