WASHINGTON DC: Almost two-thirds of patients in the US who get medical marijuana are using it as a treatment for chronic pain, a new study suggests.
That's in line with the large number of Americans who suffer chronic pain and the strong scientific evidence that marijuana is an effective pain treatment, the authors report in Health Affairs.
Thirty-three US states and the District of Columbia have legalized cannabis for medical use since 1996, and 10 states have legalized it for recreational use since 2012, the study team notes.
Patients receiving cannabis for medical purposes need a license issued in states where this is legal, and licenses require a doctor to certify that patients have a condition that qualifies for treatment with marijuana.
For the current study, researchers examined data from state registries tracking the numbers of patients using medical marijuana and the conditions they got the drug to treat. Twenty states and the District of Columbia had registries tracking total patients using medical cannabis, and 15 states tracked the conditions that qualified patients for the drug.
Overall, 65 per cent of medical marijuana patients used it for chronic pain. After that, the most common reasons patients used cannabis were for multiple sclerosis, nausea and vomiting caused by chemotherapy, and post-traumatic stress disorder.
Based on a 2017 report by the National Academies of Science that assessed the scientific evidence supporting the use of marijuana to treat specific conditions, the study team also looked at how often medical uses are evidence-based. They found uses had strong backing 86 per cent of the time.
"The vast majority of conditions for which people use cannabis have substantial or conclusive evidence of cannabis being an effective treatment," said lead study author Kevin Boehnke of the University of Michigan in Ann Arbor.
"However, that doesn't mean that it's going to necessarily be easy for them to figure out how best to use cannabis or cannabinoids to treat their conditions," Boehnke said by email.
That's because even though many states have legalized medical marijuana, the federal government still classifies it as a "schedule 1" substance with no medical use and a high potential for abuse. Unlike traditional prescription drugs, there are no clinical guidelines for medical marijuana, Boehnke said.
"Medical cannabis patients are placed in a position where they typically have no choice but to experiment to find their optimal dosing regimen," Boehnke added. "Safety is definitely a concern, especially when smoking or taking high doses of THC."
"There are still many problems with how medical cannabis is actually utilized in day-to-day medical practice, but this paper provides some reassurance that it is being used in many cases to treat the right medical conditions," said Dr Kevin Hill, director of addiction psychiatry at Beth Israel Deaconess Medical Center and a researcher at Harvard Medical School in Boston.
A nationwide patient registry would make it easier to understand how patients are using medical marijuana and whether it's safe or effective for these conditions, the study authors conclude.
In the meantime, patients should consider cannabis an option to discuss with a doctor after other traditional treatments fail, Hill, who wasn't involved in the study, said by email.
"Many physicians in specialty cannabis clinics will give certifications to anyone who will pay for it, and the level of follow-up care is often poor," Hill said.
"One way we can change this is to improve the education that healthcare professionals receive on medical cannabis so that they will feel more comfortable certifying patients when appropriate and be more likely to offer useful guidance to patients on what type of cannabis to obtain, how to dose it, and what side effects to look out for," Hill added.
"Right now, 'budtenders' often play a more important role in medical cannabis than doctors do - and that needs to change."