Chronic pain patients who use herbal cannabis daily for one-year report reduced discomfort and increased quality of life compared to controls, and do not experience an increased risk of serious side effects, according to clinical data published online ahead of print in the Journal of Pain.
Researchers at McGill University in Montreal assessed the long-term health of 216 medicinal cannabis users with chronic non-cancer pain who consumed a daily standardized dose (12.5 percent THC) of herbal cannabis compared to 215 controls (chronic pain suffers who did not use cannabis). Subjects in study were approved by Health Canada to legally use medicinal cannabis and consumed, on average, 2.5 grams of herb per day, typically via inhalation or vaporization.
Investigators reported that daily cannabis consumers possessed no greater risk than non-users to experience “serious adverse events.” Specifically, researchers identified no significant adverse changes in consumers’ cognitive skills, pulmonary function, or blood work following one-year of daily cannabis consumption. Medical cannabis consumers did report elevated risk of experiencing “non-serious adverse events” (e.g., cough, dizziness, paranoia) compared to controls; however, authors classified these to be “mild to moderate.”
Pain patients who used cannabis reported a reduced sense of pain compared to controls, as well as reduced anxiety, depression, and fatigue.
“Quality-controlled herbal cannabis, when used by cannabis-experienced patients as part of a monitored treatment program over one year, appears to have a reasonable safety profile,” authors concluded.
The study is one of the first to ever assess the long-term safety and efficacy of medicinal cannabis. A prior health review of patients receiving medical cannabis monthly from the US federal government as part of the Compassionate Investigational New Drug program similarly reported that cannabis possesses therapeutic efficacy and an acceptable side-effect profile.
Full text of the study, “Cannabis for the Management of Pain: Assessment of Safety Study,” appears online here.