Plasma concentrations of THC were measured by gas-liquid chromatography and mass spectrometry following three routes of administration and correlated with clinical effects. Plasma concentrations peaked at 3 minutes after intravenous injection and then sharply declined. The peak "high" occurred at 30 minutes while plasma concentrations were declining. This lag between plasma concentration and "high" continued during most of the span of the drug's effects. The situation was quite similar following smoking, except that peak plasma concentrations were lower. After oral administration of THC, absorption was slow, with peak concentration occurring at 1 to 2 hours. Plasma concentrations were much lower. Correlations between plasma concentrations of drug and "high" were significant but not impressive. The degree of "high" was quite variable in relation to the prevailing plasma concentration. Conjunctival injection was found so long as plasma concentration of THC could be measured. Pulse rate increases occurred at lower concentration after oral administration than after the other two routes. It is unlikely that a range of plasma concentrations can be reliably equated with impaired performance. The mode of administration will become important should THC or some homolog become a therapeutic agent.

Administration, Oral↗

PubMedDate not supplied

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.

Administration, Inhalation↗

PubMedDate not supplied

A new stimulant, prolintane hydrochloride, compared with dextroamphetamine in fatigued volunteers.

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Adolescent↗