(Categories of Cannabinoid Medicines) "They [cannabinoid medicines] fall into three categories: single molecule pharmaceuticals, cannabisbased liquid extracts, and phytocannabinoid-dense botanicals–the main focus of this article (Figure 2). The first category includes US Food and Drug Administration (FDA)-approved synthetic or semisynthetic single molecule cannabinoid pharmaceuticals available by prescription. Currently, these are dronabinol, a Schedule III drug and nabilone, a Schedule II drug. Though both are also used offlabel, dronabinol, a (-)trans-[delta]9-tetrahydrocannabinol (THC) isomer found in natural cannabis, has been approved for two uses since 1985 and 1992, respectively: the treatment of nausea and vomiting associated with cancer chemotherapy in patients who have failed to respond adequately to conventional antiemetic treatments and the treatment of anorexia associated with weight loss in patients with AIDS.10,11 Nabilone, a synthetic molecule shaped similarly to THC, has also been approved since 1985 for use in the treatment of nausea and vomiting associated with cancer chemotherapy.12,13
"The second category of cannabinoid medicines being used in the United States includes a line of cannabis-based medicinal extracts developed by several companies. The industry leader is GW Pharmaceuticals, a UK-based biopharmaceutical company whose lead product is currently undergoing FDA-approved, multisite Phase IIb clinical trials for the treatment of opioid-refractory cancer pain in the United States14 and has received prior approval for Phase III clinical trials in the United States. This botanical drug extract which goes by the nonproprietary name nabiximols has already secured approval in Canada for use in the treatment of central neuropathic pain in multiple sclerosis (in 2005) and in the treatment of intractable cancer pain (in 2007).15 It is also available on a named patient basis in the United Kingdom and Catalonia,16,17 a scheme which allows a doctor to prescribe an unlicensed drug to a particular “named patient,” and has been exported to 22 countries to date.
"The third category of cannabinoid medicines currently being used in the United States includes the Schedule I medicinal plant Cannabis sativa L. itself, which, while currently unavailable for general prescription use in the United States, is in use in the context of two active controlled clinical trials,18,19 33 completed controlled clinical trials,20-52 and one on-going, yet essentially defunct, three-decade investigational clinical study.53,54"


Aggarwal, Sunil K.; Carter, Gregory T.; Sullivan, Mark D.; ZumBrunnen, Craig; Morrill, Richard; and Mayer, Jonathan D., "Medicinal use of cannabis in the United States: Historical perspectives, current trends, and future directions" Journal of Opioid Management, (Weston, Massachusettes: May/June 2009) Vol. 5:3, pp. 153-154.