CDA Essentials 2017 • Volume 4 • Issue 6

30 | 2017 | Issue 6 I ssues and P eople Barriers to Research Relatively limited research has been conducted on the therapeutic effects of cannabis. This is due in part because cannabis is considered a Schedule II drug under the Canadian Controlled Drugs and Substances Act, but the American Food and Drug Administration considers it a Schedule I drug—meaning that there is a high potential for abuse and no approved medical use. American researchers wanting to study cannabis must therefore obtain a special license from the Drug Enforcement Agency (DEA), and then approval from the National Institute on Drug Abuse. “Schedule I drugs include heroin,” explains Dr. Jose Lança, assistant professor in the faculties of dentistry and medicine at the University of Toronto. “That is an important limitation. To conduct broad studies is very difficult, if not impossible.” Limited research means there is limited evidence of safety and effectiveness. “The classification of cannabis as a Schedule I drug creates difficulty in obtaining funding for comprehensive studies,” notes a 2016 JADA article. 2 That is why many physicians and researchers are advocating for a change in schedule, which would hopefully lead to increased research on the therapeutic effects—or absence thereof— of cannabis. As of 2016, the only American institution allowed to grow research-grade marijuana was the University of Mississippi. The DEA has since allowed applications for new sites to grow cannabis, which could improve availability of marijuana for research purposes. • Nabilone (Cesamet®): A THC capsule, nabilone is an antiemetic agent that can be prescribed for the treatment of nausea and vomiting associated with chemotherapy. 3 • Nabiximols (Sativex®): A combination of THC and CBD, this oromucosal spray is approved by Health Canada as “adjunctive treatment for the symptomatic relief of neuropathic pain in multiple sclerosis (MS) in adults.” 4 It can also be used as an “adjunctive analgesic treatment in adult patients with advanced cancer who experience moderate to severe pain during the highest tolerated dose of strong opioid therapy for persistent background pain.” 5 Another synthetic THC medication (dronabinol, Marinol®) used to be available, but manufacturer AbbVie stopped offering it in Canada in 2012. Under the 2016 Access to Cannabis for Medical Purposes Regulations (which replaces the Marihuana for Medical Purposes Regulations ), physicians may also authorize the use of marijuana or cannabis oils in patients whose symptoms do not improve with conventional medical treatments. These symptoms may include nausea and vomiting associated with chemotherapy; loss of appetite and body weight in cancer patients and those with HIV/AIDS; pain and muscle spasms associated with MS; chronic non-cancer pain; cancer-associated pain; insomnia and depressed mood associated with chronic diseases; and symptoms encountered in palliative care. 6 Two synthetic cannabinoid-based medications are currently available in Canada. Approved Medical Uses