Antiemetic efficacy of smoked marijuana - Subjective and behavioral effects on nausea induced by syrup of ipecac

Although the public debate about the legalization of marijuana has continue d for as long as 25 years, few controlled studies have been conducted to as sess its potential medical benefits. The present study examined the antieme tic effect of smoked marijuana cigarettes (8.4 and 16.9 mg Delta (9)-tetrah ydrocannabinol [THC]) compared to a highly potent antiemetic drug, ondanset ron (8 mg) in 13 healthy volunteers. Nausea and emesis were induced by syru p of ipecac. Marijuana significantly reduced ratings of "queasiness" and sl ightly reduced the incidence of vomiting compared to placebo. Ondansetron c ompletely eliminated the emetic effects of ipecac. These findings support a nd extend previous results, indicating that smoked marijuana reduces feelin gs of nausea and also reduces emesis in this model. However, its effects ar e very modest relative to ondansetron, and the psychoactive effects of mari juana are likely to limit its clinical usefulness in the general population . (C) 2001 Elsevier Science Inc. All rights reserved.