Science Cannabis

148 THE SCIENCE OF MARIJUANAExperiments in animals, however, have failed to show any consistent effectsof THC on appetite or body weight.The second approved indication for dronabinol is as an appetitestimulant to treat the loss of appetite and weight loss associated withAIDS. After a series of small-scale clinical trials gave promising results, alarger placebo controlled clinical trial was conducted in 139 such patients(Beal et al., 1995). As compared to placebo, dronabinol treatmentresulted in a statistically significant improvement in appetite after 4 to 6weeks of treatment, and this effect persisted in those patients who continuereceiving dronabinol after the end of the formal trial. There weretrends toward increases in body weight and a decrease in nausea. Thedose of Marinol® that appears to be optimum is 5 mg per day, administeredas two doses of 2.5 mg, one given 1 hour before lunch, and onegiven 1 hour before supper. Other clinical trial data suggest that dronabinolmay also benefit AIDS patients suffering nausea and loss of appetiteas a consequence of treatment with antiviral drugs. Other clinicalstudies have indicated that dronabinol causes a significant stimulation ofappetite in cancer patients, who also commonly suffer loss of appetiteand an accompanying body weight loss. In both cancer patients and inAIDS patients suffering from wasting syndrome it is difficult to knowwhether the beneficial effects of dronabinol are not due in part at least toits ability to treat the symptoms of nausea that often accompany thesesyndromes. Dronabinol does not seem likely to be of any benefit to patientssuffering from anorexia nervosa. The results of a controlled doubleblind crossover design trial in 11 such patients in which dronabinol wascompared with diazepam (Valium®) found no benefit with either drug,and dronabinol caused unpleasant psychotropic reactions in three of thepatients.As in the treatment of nausea and vomiting, the principal adverseside effect in the use of dronabinol as an appetite stimulant has been theintensity of the accompanying CNS side effects. While careful choice ofthe optimum dose and its timing relative to meals can manage these insome patients, the delayed onset of action of the orally administered drugand its long duration of action are negative features. For this reason it isnot surprising that many AIDS patients have turned to self-medication