Patients with chronic pain may experience more relief if their doctors add marijuana to their opiates-only treatment program, according to a new study at UC San Francisco. The study also suggests the combined therapy may result in the reduced use of opiates.
More than 76 million Americans suffer from chronic pain, according to the National Centers for Health Statistics. Opiates are very strong pain killing drugs that can be highly addictive.
The study, published in this month’s edition of Clinical Pharmacology & Therapeutics, was the first to examine the interaction between opiates and cannabinoids in humans. Cannabinoids are the main ingredient in cannabis or marijuana. Researchers found the combination of cannabinoids and opiates reduced pain more than using opiates alone, similar to results found in animal studies.
“Pain is a big problem in America and chronic pain is a reason many people utilize the health care system,” said the paper’s lead author, Dr. Donald Abrams, professor of clinical medicine at UCSF. “And chronic pain is, unfortunately, one of the problems we’re least capable of managing effectively.”
Abrams and his colleagues studied 21 chronic pain patients who were being treated with sustained release morphine or oxycodone. Their treatment was supplemented with cannabinoids, inhaled through a vaporizer. The original focus of researchers was to see if the opiates’ effectiveness could be increased, not whether the cannabinoids helped reduce pain.
“The goal of the study really was to determine if inhalation of cannabis changed the level of the opiates in the bloodstream,” Abrams said in a news release. “And while we were doing that, we also asked the patients what happened to their pain.”
Patients in the study inhaled vaporized cannabis for four consecutive days, while also taking either morphine or oxycodone. Researchers then looked at the level of opiates in their blood and found that levels of morphine were slightly lower, while levels of oxycodone were unchanged. Both groups of patients showed a significant decrease in their pain, with no major side effects such as nausea or loss of appetite.
“One would expect they would have less relief of pain and what we found that was interesting was that instead of having less pain relief, patients had more pain relief,” Abrams said. “This preliminary study seems to imply that people may be able to get away perhaps taking lower doses of the opiates for longer periods of time if taken in conjunction with cannabis.”
Because only 21 patients were involved in the study, Abrams says a larger one is needed. “What we need to do now is look at pain as the primary endpoint of a larger trial,” he said. “Particularly I would be interested in looking at the effect of different strains of cannabis.”
The study was supported by funds from the National Institutes on Drug Abuse and the National Institutes of Health.