Research in Canada on Cannabis for Medicinal Purposes
Earlier this year, Health Canada announced its commitment to respond to the needs of people who believe that Cannabis sativa (marijuana) may alleviate their medical symptoms and improve the quality of their lives, and to address the lack of available scientific evidence about the safety and effectiveness of marijuana. To that end, Health Canada is providing funds for several clinical trials and is establishing a licit, domestic supply of cannabis for research purposes. In October, federal Health Minister Allan Rock announced more information about his department's continued commitment to move forward with plans to support research into the medical uses of cannabis and to provide access to marijuana on compassionate grounds.
Because of the unique qualities of this plant, its current legal status, public interest in clinical research, and anecdotal claims of its potential medicinal value, Health Canada will actively facilitate clinical trials in order to address unanswered scientific questions. Depending upon the number of approved protocols, several million dollars could be committed to these research initiatives. The majority of the costs of these clinical trials will be paid by Health Canada to facilitate the gathering of the scientific data on the safety and efficacy of marijuana. Health Canada's plan to research the medical use of marijuana comprises an examination and evaluation of smoked marijuana, other marijuana extracts and components, and non-smoked marijuana.
Marijuana as Effective Medicine
Cannabis sativa was "official" in various pharmacopoeia until the late 1930s, described as analgesic-hypnotic; topical anaesthetic; antiasthmatic; antibiotic; antiepileptic; antispasmodic; antidepressant and tranquilizer; antitussive; appetite stimulant; oxytocic; preventive and anodyne for neuralgia and migraine; aid to psychotherapy; and agent to ease withdrawal from alcohol and opiates.
However, although there is much anecdotal and historical evidence, the effectiveness of marijuana for medicinal purposes has not been conclusively established using modern scientific criteria in any country. In recent years, the existing scientific and medical evidence with respect to smoked marijuana has been assessed by several governmental and health organizations including the Standing Committee on Medicine (Netherlands), the National Institutes of Health (United States), the House of Lords and the British Medical Association (United Kingdom), and the World Health Organization. Their reports state that evidence of the potential therapeutic effectiveness of marijuana is heavily anecdotal and inconclusive. They recommend that further research studies be conducted and that delivery mechanisms other than smoking be developed, the inhalation of smoke posing obvious health risks.
Other Available Drugs
Approved drugs are available in Canada for the symptomatic treatment of multiple sclerosis, glaucoma, and the nausea and loss of appetite associated with cancer chemotherapy and AIDS. Currently, 2 containing active ingredients derived from or similar to cannabis are used to conter the side effects of chemotherapy: dronabinol [delta-9-tetrahydrocannabinol] (Marinol®) and nabilone (Cesamet®), a synthetic cannabinoid. Both are scheduled as narcotics in Canada.
Dangers of Medicinal Marijuana
As with all drugs, there are health risks associated with cannabis. Although its history suggests that it has only low toxicity (with no confirmed deaths attributed to marijuana poisoning), potential health risks associated with its medical use have not been adequately examined. However, some are known and should be discussed between patient and physician when appropriate.
Securing a Source
Health Canada has developed a business plan outlining the feasibility of and necessary steps for the establishment of a licit, domestic supply of research grade marijuana for research and medical purposes. Its goal is to have such an operation in place within a year. A Health Canada Fact Sheet about developing a domestic source of research grade marijuana, Production of Marijuana in Canada for Research Purposes, is available from the Ministry.
Until a licit, domestic supply is established, Health Canada will secure a supply of research grade marijuana for clinical trials conducted in Canada. The US National Institute of Drug Abuse and a private company in the UK (GW Pharmaceuticals Ltd.) are potential sources. These sources will be accessed as soon as clinical trials are ready to begin.
Start of Clinical Trials
Health Canada will continue working with researchers to refine their protocols and to obtain the various approvals needed to conduct trials with the smoked form of marijuana. Health Canada will also facilitate requests to obtain the drug supply required. Provided that all approvals are obtained, some trials should begin early in 2000. Other projects formulated through the Medical Research Council may also begin around that time. Clinical trials conducted as part of Health Canada's research will be announced when they are ready to begin.
Design
Clinical trials study the safety and efficacy of drugs in people who might expect to benefit from the drug, should it become available in the future as an approved drug. For instance, if a drug is being studied to combat cancer, trial participants are always people with cancer. While those who design clinical trials do consider age when deciding whom to include in the trial population, there is no specific prohibition against studying drugs in people of certain ages, unless it is unethical to do so.
Clinical trials are usually designed to study a specified number of patients for a specified period of time. While there may be a number of clinical trials on marijuana over the next few years, it is unlikely that everyone who wants to join a trial will be able or eligible. As in any clinical trial, all applicants will be assessed by the investigators of the trial to determine whether they fit selection criteria as defined in the study design.
Generally, no specific limits on locations (where clinical trial participants can use the marijuana) will be imposed, unless it is defined as part of the specific research design. Strict scientific studies require assurance that the substance has been taken in a controlled setting. In addition, participants will be encouraged to exercise due care towards others and to refrain from smoking in inappropriate places.
Health Canada regulates the design of clinical trials. For those involving the use of medicinal quality marijuana , Health Canada investigators and research ethics boards will oversee the conduct of each trial to ensure that all protocols are followed and will review the outcome of the research activities when submitted for assessment of the substance's profile concerning its safety, effectiveness and quality.
The handling of marijuana by licensed dealers, researchers, practitioners and patients will follow the same controls as for any other narcotic drugs monitored by Health Canada. Because cannabis is classified as a controlled drug in Canada, its use in clinical trials must be in full knowledge of and co-operation with the Royal Canadian Mounted Police (RCMP) and other law enforcement agencies. All efforts will be made by Health Canada and those involved with the trials to secure the operation of clinical trials and control the distribution of the drug, to ensure that the marijuana intended for clinical trials is not delivered to other users.
Current Status
From June until September, Health Canada granted 16 exemptions under Section 56 of the Controlled Drugs and Substances Act. By early October, the review of another 8 applications was near completion and 80 more enquiries had been received. The Department aims to review each application within 15 working days of receiving all the required application information.
Those who obtain an exemption under Section 56 are allowed to cultivate or possess a controlled substance, activities which are otherwise illegal under Canada's Controlled Drugs and Substances Act and punishable in all Canadian jurisdictions by a maximum prison sentence of 7 years for each offence. Health Canada is aware that those who are seriously ill may need the help of others to cultivate medical marijuana, but exemptions do not include provisions for this. Health Canada will actively engage in consultations with stakeholders, including potential applicants, physicians and patient interest groups, over the coming months to examine the issue of exemptions for caregivers; to further explore this and other issues; to review the experience of applicants, practitioners and other interested parties; and to help ensure a process that is fair, compassionate and efficient.
CRIT & CTN
Since its announcement in June, Health Canada has been working with representatives of the Canadian Research Initiative of Toronto (CRIT) and the Canadian HIV Trials Network (CTN) to develop a draft research protocol for a clinical trial including marijuana for medical purposes. The protocol for this clinical trial, which is expected to involve 250 patients, is a double-blind, randomized design with 3 separate arms. Research subjects will receive either research grade cannabis in a smoked form, dronabinol capsules, or a placebo.
The protocol was submitted in September to the CTN's Scientific Review Committee for review and will also be subjected to ethical reviews by responsible bodies, including the CRIT and the CTN's National Ethics Review Committee. A regulatory review by Health Canada will also be conducted. Assuming approval of the protocol, this clinical trial is expected to commence early in 2000 and will take approximately 1 year to complete.
Medical Research Council
Health Canada has committed financial support to the Medical Research Council of Canada (MRC) to fund a 5-year program of clinical research to evaluate the efficacy and safety of marijuana, or cannabinoids, for a variety of symptoms. During the summer, the MRC notified the Canadian research community of the new research opportunity. The first of a series of Requests for Applications was subsequently posted on the MRC's web site. (The deadline for this year was 1 October 1999.) Successful research projects will be posted and funding will become available in January 2000.
Participation in Clinical Trials
Persons who are interested in participating in clinical trials should first discuss their treatment options with their primary care provider.
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