Research lacking on medical pot: doctors’ groups

‘ADVERSE EVENTS’

they need to make informed decisions around treatment, Allan said.

“I think this gives (doctors) some comfort, saying, ‘Look, here’s the evidence. It’s actually missing in a lot of places, so I can’t give it for conditions X, Y and Z,’ ” Allan said. He described medical pot as a high-risk product that should only used in rare circumstances when other, safer treatment options have been exhausted.

Health Canada data show the number of clients registered with licensed medical marijuana producers jumped to more than 200,000 as of June 2017, which is about 2.7 times greater than the 75,166 people registered at the same time last year. Registrations more than tripled in both 2016 and 2015. warning that cannabis is not an approved therapeutic product and the department does not endorse its use. The document was last updated in 2013.

The first advisory prepared by Alberta’s family physicians college, which was released Nov. 14, says the evidence is “too sparse and poor” to conclude that marijuana is effective at relieving pain. The second document, released two weeks later, describes “adverse effects” as one of the only consistent findings of the existing studies. These harms included hallucinations, paranoia, dizziness and low blood pressure.

The research likely underestimates the frequency of adverse outcomes because most studies involve patients who have a history of using pot so are less likely than the average person to experience any negative side effects, Allan said.

Some studies indicate marijuana can reduce nausea for chemotherapy patients and control spastic muscle contractions in patients with multiple sclerosis, but there is virtually no evidence of any effect on chronic anxiety or glaucoma, as is commonly cited by industry advocates.

“Some of the pain studies go for nothing more ... than five, six hours. And this is for chronic pain,” Allan said. “It’s hard to get a great feel for how someone is going to do long term on a medicine after five, six hours.”

The only evidence of marijuana being used to treat glaucoma is a single randomized study conducted on six patients, he added.

Medical colleges have released some general guidelines for primary-care providers about prescribing marijuana. Documents released by the colleges of physicians and surgeons in both British Columbia and Alberta cite the absence of reliable evidence demonstrating the effectiveness of cannabis as medication.

The Alberta college is helping put together more comprehensive provincial guidelines for prescribing medical cannabis, which it expects to release by March, Allan said.