Human urinary excretion profile after smoking and oral administration of [14C]delta 1-tetrahydrocannabinol.
The urinary excretion profiles of delta 1-tetrahydrocannabinol (delta 1-THC) metabolites have been evaluated in two chronic and two naive marijuana users after smoking and oral administration of [14C]delta 1-THC. Urine was collected for five days after each administration route and analyzed for total delta 1-THC metabolites by radioactivity determination, for delta 1-THC-7-oic acid by high-performance liquid chromatography, and for cross-reacting cannabinoids by the EMIT d.a.u. cannabinoid assay. The average urinary excretion half-life of 14C-labeled delta 1-THC metabolites was calculated to be 18.2 +/- 4.9 h (+/- SD). The excretion profiles of delta 1-THC-7-oic acid and EMIT readings were similar to the excretion profile of 14C-labeled metabolites in the naive users. However, in the chronic users the excretion profiles of delta 1-THC-7-oic acid and EMIT readings did not resemble the radioactive excretion due to the heavy influence from previous Cannabis use. Between 8-14% of the radioactive dose was recovered in the urine in both user groups after oral administration. Lower urinary recovery was obtained both in the chronic and naive users after smoking--5 and 2%, respectively.
Johansson
E
E
Department of Pharmacognosy, BMC, Uppsala, Sweden.
Gillespie
H K
HK
Halldin
M M
MM
D000280:Administration, Inhalation; D000284:Administration, Oral; D002250:Carbon Radioisotopes; D003429:Cross Reactions; D013759:Dronabinol / Q000031:analogs & derivatives / Q000378:metabolism / Q000652:urine*; D006801:Humans; D007124:Immunoenzyme Techniques; D008385:Marijuana Smoking / Q000652:urine*
D002250:Carbon Radioisotopes; C065093:4'',5''-bisnor-delta(1)-tetrahydrocannabinol-7,3''-dicarboxylic acid; D013759:Dronabinol