Monday, April 10, 2017
Physicians have little Scientific Evidence for using Medical Marijuana
Ask a teenage high school student about Marijuana and there is a good chance they know quite a bit . about it. Marijuana has become a regularly used substance for recreational use. Chances are good that the average 'user' knows far more about marijuana, THC or CBD than your physician.
Medical Schools do have pharmacology courses, where students can read the basic science and neurobiology of the molecule(s), however there are few clinical references of studies on the matter. There are plentiful articles in lay press, Internet articles about the substance.
Five patients have confided to Key West internist John Norris III, MD, that they use marijuana to relieve painful, persistent muscle spasms resulting from strokes or multiple sclerosis.
Gaps in Knowledge
Norris’s complaints highlight the knowledge gaps physicians confront when it comes to medical marijuana, now legal in 28 states, the District of Columbia, Puerto Rico, and Guam. They didn’t learn about it in medical school, and, because it is not a US Food and Drug Administration–approved drug backed by randomized controlled trials, they can’t turn to the Physicians’ Desk Reference for information about dosage, indications, and contraindications. The federal Drug Enforcement Administration (DEA) still classifies marijuana as a schedule I drug, along with heroin and ecstasy, that has a high potential for abuse and no accepted medical use. As a result, studies of its therapeutic use are limited and physicians have prohibited from prescribing it.
However the situation is changing rapidly with recent legalization of marijuana in multiple states. Abrams and his coauthors reviewed more than 10 000 scientific abstracts. They found that the strongest evidence of a health benefit from cannabis and cannabinoids is in the treatment of chronic pain and muscle spasms associated with multiple sclerosis and chemotherapy-induced nausea and vomiting.
As the number of states that have legalized medical marijuana rises, the need for research becomes even more pressing, according to a recent editorial in Lancet Oncology: “For a product rapidly becoming mainstream, clinical trials and basic research are crucial: The requirement for evidence of the benefits and risks of marijuana use will grow as access increases and regulations, including clear guidelines for safe and effective use, must be developed.”
“There’s insufficient to no evidence for most of the claims [about medical marijuana],” said University of California, San Francisco (UCSF) oncologist Donald Abrams, MD, coauthor of a new report from the National Academies of Sciences, Engineering, and Medicine on the health effects of cannabis and cannabinoids (constituent compounds in cannabis). “If you like having evidence on which to base your patient recommendations, it’s really not available.”
Abrams and his coauthors reviewed more than 10 000 scientific abstracts. They found that the strongest evidence of a health benefit from cannabis and cannabinoids is in the treatment of chronic pain and muscle spasms associated with multiple sclerosis and chemotherapy-induced nausea and vomiting.
As the number of states that have legalized medical marijuana rises, the need for research becomes even more pressing, according to a recent editorial in Lancet Oncology: “For a product rapidly becoming mainstream, clinical trials and basic research are crucial: The requirement for evidence of the benefits and risks of marijuana use will grow as access increases and regulations, including clear guidelines for safe and effective use, must be developed.” Although Abrams recommends cannabis to patients, he recognizes that many questions remain, such as the best strain to treat a particular symptom. When patients ask for his thoughts on such matters, “All I can say is I don’t know,” Abrams said. “I just advise my patients to go to the dispensary and explain to them what you would like to treat. They’re [dispensaries] on the front lines.”
Many physicians aren’t comfortable relinquishing that much control, Abrams acknowledged. However, most also don’t know the difference between CBD (cannabidiol) and THC (tetrahydrocannabinol). Although both are cannabinoids, only THC makes marijuana users high.
Physicians today lack such basic knowledge about cannabis because they never learned about it in medical school. “Physicians could prescribe cannabis in this country until 1942, when it was removed from the [US] Pharmacopoeia,” Abrams said. “There hasn’t been education about cannabis as medicine for 75 years.”
Back in 1996, California became the first state to legalize medical marijuana, but a 2-week, 12-hour elective for first-year medical students this past fall was UCSF’s first attempt to educate future physicians about cannabis as medicine, said Abrams, who taught the course.
The UCSF marijuana course was 1 of 20 electives from which students could choose. It could have accommodated 12 students, but only 6 enrolled, Abrams said, adding that he “was a little surprised I only got 6 [students] here in San Francisco.”
Pot 101 . Change us in the air
On the other side of the country, a University of Vermont (UVM) Larner College of Medicine pharmacology course, PHRM 296: Medical Cannabis, drew more than twice as many students as expected when it was first offered last spring semester.
The school had to twice change the location of the elective course, as enrollment grew to 99—filling the largest available lecture hall, said Kalev Freeman, MD, PhD, an emergency department physician and assistant professor of surgery at UVM whose wife, a botanist on the medical school faculty, co teaches the class. Thought to be the first of its kind at a US academic institution, it delves into molecular biology, neuroscience, chemistry, and physiology. Students who’ve taken it include undergraduates, medical students, physicians, and a state legislator.
Thanks to the enthusiasm of pharmacology chair Mark Nelson, PhD, Freeman said, he expects that beginning this fall, the subject of cannabis will be woven into the UVM medical school curriculum, instead of offered only as a stand-alone course. In other words, he said, when medical students study psychiatry, neuroscience, cell biology, and chronic pain, cannabis will become part of the discussion. “These kids are going to graduate from medical school, and they need to know some data,” Freeman said.
Kalev Freeman, MD, PhD is a physician-scientist with a background in molecular biology and specific research interest in inflammation and injury. He is Co-Founder of the Phytoscience Institute and the Medical Director of Vermont Patients Alliance Inc., a non-profit plant-based pharmaceutical research center that serves over 800 patients with debilitating medical conditions. He is also the co-director of the Cannabis Science and Medicine Program the University of Vermont Medical School. Dr. Freeman completed his BA at the University of Michigan, and both his MD and PhD at the University of Colorado, where he specialized in molecular biology.
Cannabis . Testing for Public Safety, A course prepared for the Vermont Legislature
Physicians are cautioned not to use marijuana which would effect their practice of medicine and certainly not when on duty.