August 30, 2010

Study Claims Cannabis Reduces Chronic Pain

Individuals who are suffering from chronic neuropathic pain caused by damage to the nervous system could find relief by smoking cannabis, according to a new study published in the Canadian Medical Association Journal (CMAJ) on Monday.

The paper, entitled "Smoked cannabis for chronic neuropathic pain: a randomized controlled trial," was the product of research by a team of experts from McGill University Health Centre (MUHC) and McGill University. As part of their trial, they studied the effect of inhaled cannabis on 21 participants who were at least 18 years of age (with a mean age of 45.4) and experienced chronic nerve pain.

The adults were given tetrahydrocannabinol (THC) at four different potencies (0-percent, 2.5-percent, 6-percent, and 9.4-percent) over four 14-day trial periods.

"Participants inhaled a single 25-mg dose through a pipe three times daily for the first five days in each cycle, followed by a nine-day washout period," the researchers wrote in the abstract section of their report. "Daily average pain intensity was measured using an 11-point numeric rating scale. We recorded effects on mood, sleep and quality of life, as well as adverse events."

"We found that 25 mg herbal cannabis with 9.4% THC, administered as a single smoked inhalation three times daily for five days, significantly reduces average pain intensity compared with a 0% THC cannabis placebo in adult subjects with chronic post traumatic/post surgical neuropathic pain," lead author Dr. Mark Ware, the Director of Clinical Research at the Alan Edwards Pain Management Unit of MUHC, said in a Monday press release.

Furthermore, Ware notes that they also recorded "statistically significant improvements in measures of sleep quality and anxiety," though their report also noted that some side effects--including headache, dry eyes, burning sensation in areas of neuropathic pain, dizziness, numbness and cough--were observed when participants received the 9.4-percent THC treatment.

"The authors should be congratulated for tackling the question of whether cannabis helps in neuropathic pain, particularly given that the regulatory hurdles for their trial must have been a nightmare," Dr. Henry McQuay of Oxford University said in a related commentary, also published by CMAJ. "If patients are not achieving a good response with conventional treatment of their pain, then they may, reasonably, wish to try cannabis."


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