Jan 02, 2017
The challenges of medical cannabis research
A researcher is concerned that the research on cannabis will continue to focus on the social harms associated with recreational use and that the potential therapeutic benefits of medical cannabis will get short shrift
Whenever Lynda Balneaves tells people she studies the medical use of cannabis, she braces herself for the usual reaction. Laughter. Then a request for samples — or a comment suggesting she’s a pothead.
“But then it gets serious,” says Balneaves, an associate professor at the University of Manitoba’s college of nursing in the Rady faculty of health sciences. “People are starting to realize that medical cannabis has become a very big topic in Canada. There’s a lot of questions about this and a lot of unknowns.”
The prime minister’s commitment to legalize, regulate and restrict marijuana has widened the spotlight on cannabis as both a recreational drug and a therapeutic agent. It has also left nurses and other health-care providers wondering about their role and seeking answers to a long list of questions about the potential therapeutic value of cannabis along with the most effective medical dosage and route of administration.
“Right now we don’t understand what strains are appropriate, what dosage is appropriate, what type is best— vaporization, smoking or an edible,” says Balneaves. “We need to do much more research on it.”
For Balneaves, who studies how Canadians are accessing and using medical cannabis, the federal government’s promise to legalize marijuana heralds a cultural shift she says she hopes will change the attitude that has dogged research into this area throughout her career. “It’s still quite a stigmatized medicine.”
Much of the cannabis research to date has focused on the social harms and physiological risks associated with recreational use. The limited research on the medical use of cannabis has been conducted on pharmaceutical derivatives such as nabilone. “As such, we have a gap in knowledge about using the whole plant in some form to treat illness and relieve symptoms and side effects,” Balneaves says.
One reason, she says, is that the illegal status of cannabis has made it difficult for researchers to obtain and study the whole plant. As well, physicians have been reluctant to refer patients to clinical trials, and researchers have had trouble attracting funding to conduct large studies. “A lot of review panels don’t necessarily see this as a line of study that they think is important. They think the social risks outweigh the potential benefits.”
Statements issued by the American and Canadian medical establishment bolstered the view that cannabis was not worth studying. Initially, the American Medical Association (AMA) and the Canadian Medical Association (CMA) stated there was little evidence that cannabis was effective for pain control, nausea relief or other medicinal purposes. The AMA supported cannabis’s status in the U.S. as a Schedule I controlled substance, indicating there was a high potential for abuse and harm.
However, in 2013 the AMA issued a policy statement calling for a review of this status and for
further adequate and well-controlled studies of marijuana and related cannabinoids in patients who have serious conditions for which preclinical, anecdotal, or controlled evidence suggests possible efficacy and the application of such results to the understanding and treatment of disease.
Two years later, in July 2015, JAMA published a group of medical research papers and reviews that indicated there was evidence to support the use of medical cannabis in some instances for chronic pain and neuropathic pain and for spasticity due to multiple sclerosis.
The CMA is still not convinced that physicians should be supporting the use of cannabis for patients. In its August 2016 submission to the task force studying legalization of cannabis, the association argued that
clinical evidence of medical benefits is limited and there is very limited guidance for the therapeutic use, including indications, potency (levels of THC, CBD), interactions with medications and adverse effects.
The good news, from Balneaves’ perspective, is that the CMA is now urging Health Canada to support rigorous research into the effects of using cannabis for medical purposes. Still, she worries that once cannabis is legalized, many physicians may vacate the medical cannabis arena, particularly because of the lack of dosage and administration guidelines. This will leave many patients self-medicating with no oversight.
That’s where Balneaves believes nurses could play a bigger role. They are ideally placed to discuss with patients the potential therapeutic benefits of using medical cannabis and to learn the social and health contexts driving people to use it, she says. If patients are using cannabis, either recreationally or therapeutically, nurses should be following up with them to see if it is helping or causing harm.
It is important, she says, that nurses first educate themselves about medical cannabis through online courses such as those offered by the Canadian Consortium for the Investigation of Cannabinoids. They should also familiarize themselves with the evidence that exists, particularly as it relates to patients living with pain, nausea and vomiting from HIV/AIDS or cancer treatment, or with muscle spasms or seizures from multiple sclerosis, epilepsy and other illnesses.
Nurses also have a responsibility to inform patients about the risks, she adds. There is growing evidence to suggest that the use of cannabis can worsen mental health conditions, can induce dependency and can negatively affect the developing brain of those under age 25. “We don’t yet know how the health risks differ when individuals are smoking, vaping or using an edible.” People who have asthma or other conditions that impair lung function should also be made aware that smoking cannabis may worsen those conditions. If a patient reports consuming so much cannabis that it has affected work or school, sense of motivation, ability to show up on time or maintain a job or a relationship, nurses need to intervene and talk with the person about those effects.
Although there are no evidence-based guidelines on dosage, most physicians and NPs who authorize the use of medical cannabis will suggest patients start out on a low dose, keep a diary to track how much symptom relief that dose provides and increase it gradually, if needed.
As of the end of September, almost 100,000 Canadians were registered in Health Canada’s medical marijuana program. Many more than these are recreational users, and it is this use that has been the focus of much of the Canadian research and policy to date.
The potential harms of recreational cannabis use took the spotlight at a meeting in October convened by the Canadian Centre on Substance Abuse and attended by policy-makers, law enforcement personnel, researchers and health-care professionals. Balneaves was there as a CNA representative and a researcher and says the goal was to set a national agenda for research on the health effects of non-medical cannabis, in response to pending legalization in Canada. Public safety, mental health, health promotion, prevention and harm reduction were identified as the key themes for future research. Balneaves says she wishes medical cannabis received as much attention and that she doesn’t want to see it lost as a research priority in Canada as a result of legalization. She is working with colleagues on developing education programs for NPs, to support them in clinical decision-making regarding medical cannabis.
While attending a social event last year, Balneaves met the relatives of a man who has a brain tumour and is using cannabis to manage his disease. Unlike the people who initially snigger when she explains what she studies, this family asked her right away about the latest medical cannabis research. “That’s often the response I get from patients and their family members; they take medical cannabis seriously,” she says. “It is keeping the patient comfortable and improving quality of life, so they don’t see anything funny about it at all.”