Pubdate: Fri, 16 Feb 2018
Source: Globe and Mail (Canada)
Copyright: 2018 The Globe and Mail Company
Author: Mike Hager
Page: A6


New medical cannabis guidelines for family doctors stress that they
should authorize marijuana for only a small fraction of patients
because many of its reported benefits have not been proved by rigorous
clinical trials.

The guidelines, published Thursday in the Canadian Family Physician
journal, warn that the number of randomized studies backing up the use
of cannabis to fight various ailments is "extremely limited or
entirely absent." The scientific evidence dictates that doctors should
recommend the drug only when treating a handful of very specific
medical conditions such as: chronic nerve pain, palliative cancer
pain, muscle stiffness associated with multiple sclerosis or spinal
cord injuries and the nausea and vomiting brought on by chemotherapy,
according to Mike Allan, a professor of medicine at the University of
Alberta and project lead for the guidelines.

Even then, patients should first consider synthetic cannabis pills and
sprays now available at pharmacies before purchasing dried cannabis or
oil products through Health Canada's mail-order system.

"We felt this was an area that was crying out for some guidance and
assistance for front-line clinicians," said Dr. Allan, who added that
patients' interest in the drug has been exploding as the legalization
of recreational cannabis is expected this summer. "The biggest
take-home message about the guidelines is: We have so little
high-quality research, which is a real challenge."

The committee of nine medical professionals and one patient
representative that drafted the guidelines found little to no
acceptable clinical evidence that cannabis helps other conditions
commonly cited by patients such as arthritis and anxiety or
depression, said Dr. Allan, who also practises part time as a family
physician in Edmonton. The guidelines also state that "common and
consistent" side effects of using medical cannabis include drowsiness,
dizziness and confusion.

The guidelines mirror a U.S. review of existing science published last
year by the National Academies of Sciences, Engineering and Medicine
that outlined nearly 100 conclusions about the benefits and harms of
cannabis on a range of public health and safety issues. The federal
panel's report stated that marijuana can almost certainly ease chronic
pain and might help some people sleep, but it may also raise the risk
of developing schizophrenia and trigger heart attacks.

It ended with a call for more scientific information about cannabis so
that healthcare professionals and policy makers can make sound
decisions because the current lack of evidence "poses a public health

Cannabis research has often been restricted because it has long been
scheduled as an illegal narcotic and big pharmaceutical companies have
not funded many trials because the plant cannot be patented like other

Mark Ware, a McGill University pain researcher and vice-chair of
Canada's recent federal panel on marijuana legalization, said the new
guidelines reiterate much of what is already known - or unknown -
about cannabis and underscore the desperate need for more clinical

"The sad truth is there haven't been many new studies in the last two
or three years so all of these reviews are looking at the same body of
data," Dr. Ware said. Last month, the federal government unveiled
$1.4-million in total for 14 projects on a wide range of cannabis
research aimed at helping Canadians understand the impact of the
coming change to the country's drug laws.

Dr. Ware questioned the new guidelines' recommendation that doctors
turn to pharmaceutical cannabinoids before authorizing patients to use
cannabis, saying those medicines are often prescribed off-label
despite a lack of evidence they work for many conditions.

"Because it's available in pharmacies, that makes it more acceptable
to prescribe?"
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