Researchers in the province of Quebec, Canada, have launched a registry for users of medical cannabis that they hope will allow physicians to monitor patients' safety and improve their ability to manage its use.
The registry is a joint effort by the Research Institute of the McGill University Health Centre (RI-MUHC) and the Canadian Consortium for the Investigation of Cannabinoids (CCIC).
The project represents the world's first research database on the use of cannabis for medical purposes and places the province at the forefront of research in the field of medical cannabis, according to a statement issued by McGill University.
Health Canada estimates that more than 40,000 Canadians legally consume cannabis to relieve symptoms from diseases such as multiple sclerosis, HIV, cancer, or epilepsy.
"It's clear to anyone who starts to look at medical cannabis research and the needs for clinicians to understand the drug and its side effects why we need such a registry," said Mark Ware, MD, from the Departments of Family Medicine and Anesthesia at McGill University, who is head of the registry project.
"Marijuana, or cannabis, as I prefer to call it, has been studied for those who use it recreationally, but when you talk about patients who have multiple sclerosis or spinal cord injury or epilepsy or other severe, chronic diseases, the risks that the drug may interact with existing therapies or with their other conditions have never been properly studied," Dr Ware told Medscape Medical News.
"We are appealing to physicians who are prepared to offer cannabis to their patients to become collaborators in this research registry project," he said.
"With appropriate training and understanding of what the registry is trying to do, why it is important to obtain consent from the patient, how to do that, how to complete the forms and transmit them properly, there is a necessary training step," Dr Ware said.
"Once physicians learn how to do these things, they will become collaborators, and along with their patients, for whom they authorize cannabis, they can then enroll them and enter their data into the registry," he said.
Established Model
The registry is using a pharmacovigilance model, Dr Ware said.
"This is a fairly well-established initiative in trying to follow drugs in the real world for both safety and benefit, so we will be looking for adverse event reporting," he said.
At the same time, the registry project will be seeking information on potential benefits of medical cannabis.
"We want to balance any adverse events with benefits, and to this effect, the physicians will administer a questionnaire to determine how their patients' function is changing over time, either for better or for worse," he said.
Almost all of the medicines patients are prescribed have been studied and approved through a rigorous process with data from randomized clinical trials attesting to their efficacy.
However, medical cannabis has not been studied in this way, nor is it likely to be so studied in the foreseeable future, Dr Ware said.
"There are, in fact, very few clinical trials on medical cannabis, with very few numbers, and the registry may not answer the question about efficacy, because we typically resolve that question with randomized, controlled trials, the experimental design of choice for determining whether a drug is efficacious in a particular symptom or not," he said.
Safety a Major Concern
However, the registry is expected to answer questions about the safety of cannabis.
"Patients and their clinicians are worried about safety, and the reality is, you cannot address safety issues until you follow a large number of people for a long period of time. Many physicians wonder, does cannabis work or not? But if the patient says it does, they are okay with that as long as the patient is not harming him- or herself.
"Safety is a major concern, and these are patients with chronic diseases who may use this drug for a long time. It is important that we put into place a mechanism to at least follow them for safety issues," Dr Ware said.
The Quebec registry, which is formally called A Database on the Use of Dried Cannabis for Medical Purposes Established for Research Purposes, will be based on the planned collection of observational data for a total of 10 years, with collection of clinical data for 4 years following the recruitment of each participant.
The registry's first aim is to establish an infrastructure for research to produce new knowledge on dried cannabis use, specifically, studies on its potential risks and benefits.
Secondary aims are to implement a scientific mechanism to generate new research questions on the subject and to foster collaboration among researchers conducting projects on cannabinoid use, not just from Quebec but from other Canadian provinces, the United States, and worldwide, by giving them a means to share research data.

Dr Mark Ware
"The data collected will not have any identifiable patient information, to protect patients' privacy. Anonymous questionnaire data will be entered into a secure electronic database that will be hosted and managed by the RI-MUHC," Dr Ware said.
"The CCIC is proud to work with Dr Ware on this province-wide project that will serve as a model for many other countries in the world," John Clark, MD, from the Department of Anesthesiology, Dalhousie University, Halifax, Nova Scotia, Canada, and president of the CCIC board of directors, said in a statement.
The CCIC is a nonprofit organization composed of physicians and researchers that aims to advance the understanding of the role of cannabinoids in health and disease through research and education.
Fantastic Idea
"I think this registry is a fantastic idea ― this prospective data collection will provide a wealth of detailed and reliable information that would inform on the long-term consequences of marijuana use, both potential positive and negative outcomes," said Subroto Ghoze, MD, PhD, from University of Texas Southwestern Medical Center, in Dallas, who was asked by Medscape Medical News to comment on the new registry.
From the psychiatric standpoint, for example, there is an association between marijuana use and later onset of psychosis. This registry would allow researchers to delve into this association in more specific detail, such as age of use and amount and frequency used, and might identify individuals at particular risk or those who are susceptible to the effects of cannabis.
Dr Ware and Dr Ghoze report no relevant financial relationships.
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Cite this: World's First Medical Cannabis Registry Launched - Medscape - May 18, 2015.
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