Recent state regulations (eg, in New York, Illinois) allow medical cannabis as a substitute for opioids for chronic pain and for addiction. Yet the evidence regarding safety, efficacy, and comparative effectiveness is at best equivocal for the former recommendation and strongly suggests the latter—substituting cannabis for opioid addiction treatments is potentially harmful. Neither recommendation meets the standards of rigor desirable for medical treatment decisions.
States that permit medical marijuana as an alternative to opioids for chronic pain and for addiction are getting ahead of the evidence, according to Journal of the American Medical Association associate editor Richard Saitz, MD, MPH. Writing with Keith Humphreys of the Veterans Affairs Health Services Research and Development Center, he argues that safety and efficacy findings to date are not compelling enough to warrant policy changes. For neuropathic and other pain, the pair note, cannabis studies are characterized by small sample populations, brief followup periods, and a lack of focus on the most common causes of pain. Moreover, Saitz and Humphreys can find no prospective evidence of any benefit from treating opioid addicts with cannabis—although they say research does point to potential harms. While no one is likely to die from a cannabis overdose, there is a risk for addiction—not only with marijuana but with other substances. Results of systematic reviews also point to an elevated risk of car crashes, cognitive impairment, structural brain changes, and psychotic symptoms with marijuana. Still, the authors believe cannabis-derived medical treatment is worth investigating further—but under the same rigorous conditions that apply to other novel therapies. That means cannabis trials should follow national standards, provide comparative evidence, and delegate clinical recommendations to physicians, pharmacists, and other experts, they conclude.