Chronic pain eased by cannabis
13 Dec 2011 by Evoluted New Media
Patients with chronic pain may experience greater relief if doctors add cannabinoids to an opiates-only treatment plan suggests research from the University of California San Francisco.
In the first study of its kind, researchers examined the interaction between cannabinoids and opiates. They studied 21 patients with chronic pain – ten who were being treated with sustained-release morphine and 11 on long-acting oxycodone – whose treatment was supplemented with controlled amounts of cannabinoids inhaled through a vaporiser.
Researchers obtained opiate levels from patients at the start of the study, and then exposed them to vaporised cannabis for four consecutive days. On the fifth day they looked again at the opiate level in the bloodstream.
“The goal of this study really was to determine if inhalation of cannabis changed the level of the opiates in the bloodstream,” said Donald Abrams, professor of clinical medicine a UCSF.
“The way drugs interact, adding cannabis to the chronic dose of opiates could be expected either to increase the plasma level of opiates or to decrease the plasma level of opiates or to have no effect. And while we were doing that, we also asked the patients what happened to their pain.”
The level of morphine was slightly lower in the patients, and the level of oxycodone was virtually unchanged.
“One would expect that they would have less relief of pain and what we found that was interesting was that instead of having less pain relief, patients have more pain relief,” Abrams said. “So that was a little surprising.”
The morphine group came in with a pain score of 35 on day one, which decreased to 24 on day five – a 33% reduction. The oxycodone group had an average pain score of 44 on day one, which fell to 34 – a drop of 20%.
“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,” Abrams said.
Abrams is now interested in looking at the effect of different strains of cannabis and at pain as the primary endpoint of a larger trial.
