Education Key When Considering Prescribing Medical Marijuana
Much has been published on medical marijuana within the past year, but the data on safety are not encouraging and data on clinical efficacy are very limited.
Clinicians should educate themselves and their patients if they choose to use medical marijuana in their practice, according to Michael E. Schatman, PhD, a clinical psychologist who has spent decades working in multidisciplinary chronic pain management. He presented on this topic during a session this week.
Much has been published on medical marijuana within the past year, but the data on safety are not encouraging and data on clinical efficacy are very limited. Generally, the quality of research from countries like Israel and Brazil has been much better than that from the United States because the laws governing research are different in those countries, Dr. Schatman explained. However, help may be on the way in the form of the 21st Century Cares Act. The law was recently amended to facilitate medical cannabis research, rescheduling it from a 1 to a 1-R designation, likely “making it easier to do good research,” he said. The act calls for an additional $1.75 billion in National Institutes of Health funds.
Currently, all federally funded medical marijuana research must use low-grade marijuana grown at the University of Mississippi. He said this marijuana comes in 3 different dosage strengths: low at 1.29% tetrahydrocannabinol (THC), moderate potency at 3.53%, and high potency at 7%.1
These potencies present a challenge, Dr. Schatman said, because published data from Mehmedic et al showed that the average THC of government-seized marijuana increased from 3.4% to 8.8%,2 meaning that the cannabis that is being tested for medicinal use is not the same as what many patients may be using recreationally. Dispensaries carry cannabis strains as high as 33% THC.
There are new clinical efficacy data related to medical marijuana, Dr. Schatman noted, but they are generally data from other countries. He cited one study out of Australia that concluded medical marijuana was associated with a 70% reduction in chronic pain symptoms. However, he cautioned that this study made no mention of the constituents of the marijuana used or the types of pain.3
An American study of medical marijuana for patients with diabetic neuropathic pain concluded that a 7% THC formulation worked better than a 4% or a 1% formulation, but it also resulted in more cognitive impairment.4