Delta-9-Tetrahydrocannabinol: Metabolism and Disposition in Long-Term Marihuana Smokers

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Science  02 Jul 1971:
Vol. 173, Issue 3991, pp. 72-74
DOI: 10.1126/science.173.3991.72


Radioactively labeled delta-9-tetrahydrocannabinol (δ9THC) administered intravenously to chronic marihuana smokers disappeared from the blood plasma with a half-life of 28 hours as compared to 57 hours for nonusers of marihuana. Apparent volumes of distribution did not significantly differ between the two groups. Within 10 minutes after administration of δ9THC, 11-hydroxy-δ9THC is present in the plasma of nonusers and chronic users. This metabolite was also present in urine and feces of nonusers and long-term marihuana smokers. In addition, polar metabolites were excreted in urine and feces of both groups for more than 1 week.