Interactions of Marihuana and THC with Other Drugs

Abstract

Marihuana use involves more than one substance. Not only is tetrahydrocannabinol (THC), the active psychoactive component, present, but also one or both other major cannabinoids, cannabidiol (CBD) and cannabinol (CBN).At present, evidence indicates that neither of these other two cannabinoids affects the action of THC. For practical purposes, THC alone is a model for the psychoactive action of marihuana. Alcohol is the social drug most used with marihuana, such use often being deliberate. Both have similar intoxicating effects, but these additive effects have not led to serious interactions. Stimulants often reverse some of the effects of THC, but the “high” from cocaine may be additive to that from THC. The interaction is so mild that no pattern of combined use has appeared. The same is true of the hallucinogen phencyclidine. So far as therapeutic drugs are concerned, few data are available. Although medical marihuana is not officially approved, marihuana has been tried empirically for treating a variety of medical disorders, such as nausea and vomiting associated with cancer chemotherapy, wasting syndrome associated with AIDS, and spasticity from neurological diseases. In each instance, other drugs are also present. So far, no adverse interactions from such use have been reported. However, this might not reflect the true prevalence. Unless one looks for something, one is not likely to find it.