“The growing body of evidence that marijuana (cannabis) may be effective as a pain reliever has been expanded with publication of a new study in The Journal of Pain reporting that patients with nerve pain showed reduced pain intensity from smoking marijuana.

Researchers at University of California Davis examined whether marijuana produces analgesia for patients with neuropathic pain. Thirty-eight patients were examined. They were given either high-dose (7%), low-dose (3.5%) or placebo cannabis.

The authors reported that identical levels of analgesia were produced at each cumulative dose level by both concentrations of the agent. As with opioids, cannabis does not rely on a relaxing or tranquilizing effect, but reduces the core component of nociception and the emotional aspect of the pain experience to an equal degree. There were undesirable consequences observed from cannabis smoking, such as feeing high or impaired, but they did not inhibit tolerability or cause anyone to withdraw from the study. In general, side effects and mood changes were inconsequential.

It was noted by the authors that since high and low dose cannabis produced equal analgesic efficacy, a case could be made for testing lower concentrations to determine if the analgesic profile can be maintained while reducing potential cognitive decline.

In addition, the authors said further research could probe whether adding the lowest effective dose of cannabis to another analgesic drug might lead to more effective neuropathic pain treatment for patients who otherwise are treatment-resistant.”

http://www.sciencedaily.com/releases/2008/06/080626150628.htm