Metabolism of tetrahydrocannabinol in frequent and infrequent marijuana users.
delta 9-tetrahydrocannabinol (THC), 11-nor-9-carboxy-delta 9- tetrahydrocannabinol (THC-COOH), and its O-ester glucuronide were measured in plasma by GC/MS and in urine by GC/MS and enzyme immunoassay after frequent and infrequent marijuana users were given 5 mg THC intravenously. Plasma THC concentrations were detectable 4-5 h after infusion using solid-phase columns for drug extraction and gas chromatography/mass spectrometry (GC/MS) for detection and quantification. THC-COOH and its O-ester glucuronide were analyzed for 12 days. Concentrations were higher in the plasma and urine of frequent marijuana users. The ratio of THC-COOH to its O-ester glucuronide in plasma was greater than 2 in both frequent and infrequent users 2 to 30 min postinfusion. Ratios for the subsequent 12 days were less than 2. A ratio of less than 1 for total THC-COOH/THC occurred only before 45 min for both frequent and infrequent users. Physiological, psychological, and pharmacokinetic data revealed few differences between frequent and infrequent marijuana users.
Kelly
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School of Public Health, University of California-Berkeley 94720.
Jones
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RT
D000328:Adult; D001794:Blood Pressure / Q000187:drug effects; D001831:Body Temperature / Q000187:drug effects; D002849:Chromatography, Gas; D003404:Creatinine / Q000652:urine; D013759:Dronabinol / Q000031:analogs & derivatives / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology / Q000652:urine; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007275:Injections, Intravenous; D008297:Male; D002189:Marijuana Abuse / Q000378:metabolism*; D008875:Middle Aged
C016780:11-nor-delta(9)-tetrahydrocannabinol-9-carboxylic acid; C026502:delta(9)-tetrahydrocannabinol-11-oic acid glucuronide; D013759:Dronabinol; D003404:Creatinine