Science Cannabis

140 THE SCIENCE OF MARIJUANAeffects and the intoxicant actions of THC result from activation of thesame CB1 receptors in the central nervous system. Only one companypersisted with this research long enough to produce a marketed product—nabilone(Cesamet®), (Fig. 2.2). Nabilone is a potent analogue ofTHC, which scientists at the Eli Lilly Company believed might have animproved separation of the desired therapeutic effects from psychotropicactions. Unlike dronabinol, nabilone is a stable crystalline solid, and forhuman use the drug is prepared in solid form in capsules containing 1mg of nabilone that are taken by mouth, and the dose is usually 1 or 2mg twice a day.Preliminary clinical studies in the treatment of anxiety gave promisingresults, but the company decided to focus on the treatment of nauseaand vomiting in patients undergoing cancer chemotherapy as the primarytarget. They carried out the most complete series of controlledclinical trials so far undertaken on any cannabinoid, as described below(for review see Lemberger, 1985)What Are the Medical Targets for Cannabis?Nausea and Vomiting Associated with Cancer ChemotherapyIronically the condition for which there is the strongest scientific evidencefor beneficial effects of cannabis-based medicines is also now nolonger an area of pressing medical need since new and even more powerfulantisickness drugs have become available recently. When the cannabinoidsdronabinol and nabilone were first being tested, in the 1970sand early 1980s, however, matters were different. The treatment of cancerwith more and more powerful drugs to suppress the growth of tumorcells advanced considerably during the 1960s and 1970s. Although thenewer chemotherapy drugs were increasingly effective as anticanceragents they brought with them severe side effects. As the 1997 BritishMedical Association Report puts it:One of the most distressing symptoms in medicine is the prolonged nauseaand vomiting which regularly accompanies treatment with many anti-cancer