June 28 -- FRIDAY June 27 (HealthDay News) -- Drugs that contain compounds called cannabinoids from the marijuana plant don't increase the risk of serious side effects but are associated with an increase in some non-serious side effects, Canadian scientists report.
The researchers at McGill University in Montreal and the University of British Columbia (UBC) examined adverse events reported in 31 clinical studies of cannabinoid medications conducted between 1966 and 2007.
The adverse events were grouped as serious or non-serious. Serious adverse events included those that led to hospitalization, disability or death. Non-serious adverse events included dizziness and drowsiness.
"Overall, we found an 86 percent increase in the rate of non-serious adverse events among the patients treated with cannabinoids compared to the patients in the control groups," Dr. Mark Ware, a neurosciences researcher at the Research Institute of the McGill University Health Centre, said in a prepared statement.
Most of the non-serious side effects were mild to moderate in severity.
The study was published in the June 16 issue of the Canadian Medical Association Journal.
Cannabinoids have been shown to help treat chronic pain from diseases such as cancer, multiple sclerosis, arthritis and fibromyalgia. The drugs also stimulate appetite and relieve nausea, according to background information in the study.
Doctors must balance the benefits of these drugs against possible side effects, the researchers said.
"We have summarized the adverse events from these studies to help educate physicians and patients about the possible risks of medical cannabinoids. We cannot extend these results to smoked cannabis or recreational use. That will require further research," Dr. Jean-Paul Collet, senior researcher at the Child & Family Research Institute and director of the Centre for Applied Health Research and Evaluation at British Columbia Children's Hospital, said in a prepared statement.
The National Pain Foundation has more about cannabinoids.
SOURCE: McGill University, news release, June 16, 2008