Cannabis: pharmacology and interpretation of effects.

A selective introductory review of the Cannabis literature is presented. Subjects reviewed include the relative psychoactivities of Cannabis constituents, the disposition and distribution of THC and its metabolites, the relative psychoactivities of THC metabolites, and the use of cannabinoid concentrations in physiological fluids in interpretations of the significance of Cannabis-induced effects. The pharmacology of cannabinoids in humans is emphasized.