Dr. Ronald J. Ellis, Associate Professor of Neurosciences at the University of California, San Diego School of Medicine, has revealed that the study looked at 28 HIV patients with neuropathic pain not adequately controlled by other pain-relievers, including opiates.
Reporting the study in the journal Neuropsychopharmacology, the researchers have revealed that the proportion of subjects achieving pain reduction of 30 percent or more was greater for those smoking cannabis than those smoking the placebo.
"Neuropathy is a chronic and significant problem in HIV patients as there are few existing treatments that offer adequate pain management to sufferers. We found that smoked cannabis was generally well-tolerated and effective when added to the patient's existing pain medication, resulting in increased pain relief," Ellis said.
Overall, the research was carried out in five study phases over seven weeks.
During two five-day phases, randomly selected participants smoked either cannabis or placebo cigarettes made from whole plant material with cannabinoids (the psychoactive compound found in marijuana) removed, both provided by the National Institute on Drug Abuse.
Standardized tests measuring analgesia (lessened pain sensation), improvement in function and relief of pain-associated emotional distress were used to see the outcome.
Ellis said that cannabis was found to be associated with an average reduction of pain intensity from 'strong' 'to mild-to-moderate' in cannabis smokers.
The researcher further said that cannabis was also associated with a sizeable (46% versus 18% for placebo) proportion of patients reporting clinically meaningful pain relief.
The study's findings are consistent with and extend other recent research supporting the short-term efficacy of cannabis for neuropathic pain, also sponsored by the CMCR.
"This study adds to a growing body of evidence that indicates that cannabis is effective, in the short-term at least, in the management of neuropathic pain," said Dr. Igor Grant, professor of psychiatry and director of the CMCR.