Pediatricians warn evidence doesn’t support marijuana prescriptions

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There is little evidence supporting the use of medical cannabis in children and most front-line doctors should not be prescribing the drug to young people, the Canadian Pediatric Society (CPS) warns in a new policy statement.

Michael Rieder, chair of the society's drug therapy and hazardous substances committee and author of the new statement, says the federal government should "revisit" the status of medical marijuana to improve how it is prescribed and research what regulatory system would work best.

The CPS decided to publish a statement because of the growing interest in the potential of medical cannabis and the discussions surrounding the legalization of marijuana. Although some anecdotal evidence paints a rosy picture of cannabis's ability to treat epilepsy or other serious conditions in children, the drug can also cause serious side effects. For that reason, the CPS is urging caution until more research can be used to make informed decisions around what cannabis can effectively treat, who should get it and what the dosing should be like.

"To imagine that medical marijuana is risk-free is delusional," Rieder said. "Is it an option for some children? Probably. But drug use should be guided by best principles of use and risk."

Earlier this year, the story of Sandra Wilkinson's daughter made national headlines when the girl's Alberta doctor would no longer provide a prescription for medical cannabis. The girl had been taking dozens of anti-convulsive pills and was still suffering numerous life-threatening seizures. Cannabis oil was the only thing that helped. Wilkinson and her daughter travelled to St. Catharines, Ont., in order to get a new prescription.

Those sorts of anecdotal reports are the extreme, Rieder notes. In that instance, the girl did not benefit from any other treatment. While compelling, the story does not mean medical cannabis should be made a front-line treatment, he said.

"The number of kids who are going to benefit … is probably very small," Rieder said.

Cannabinoids such as tetrahydrocannabinol are the compounds in cannabis that are believed to have therapeutic effects. The cannabinoids work by acting on receptors in the body. Yet, there is little comprehensive scientific data on the effects of cannabis as a therapeutic agent with the potential to treat many diseases. Part of the reason is that it has been difficult for researchers to get approval to study an illicit substance.

But until more work is done, it is premature and potentially dangerous to widely prescribe medical cannabis to young people, according to the CPS. The new policy notes that no studies have shown cannabis to be safe or effective to treat pain or nausea in children.

Jason MacDougall, a professor in the department of pharmacology and anesthesia at Dalhousie University in Halifax, agrees that the best approach is prudence.

"We have to be very vigilant about how we administer these drugs, just like any other sort of drugs with psychoactive side effects, to children and adolescents," said MacDougall, who is studying the impact of medical cannabis on arthritis pain. "I think there's still promise and still opportunity there, but we have to be very cautious."

Rieder said the only doctors prescribing medical cannabis to young people should be neurologists, who specialize in conditions the drug may be used to treat, such as epilepsy. Even then, patients must be monitored closely and have a very clear treatment goal in mind, he said.

Cannabis can have serious side effects and several studies have shown that it causes changes in the brain of young people and may make them vulnerable to psychosis. It's unclear whether those risks apply only to people who are genetically predisposed to mental illness.

In addition to its word of caution about prescribing, the Canadian Pediatric Society argues that the federal government should regulate the medical marijuana industry more strictly and create improved oversight measures, similar to what is in place for the pharmaceutical industry, in order to protect public safety.