A recent study conducted by researchers at the University of New South Wales (UNSW) Sydney challenges the idea that cannabis could be effective for the treatment of chronic pain unrelated to cancer.
Published in July 2018 by The Lancet Public Health, the study entitled "Effect of cannabis use in people with chronic non-oncologic opioids prescribed for pain: findings of a prospective 4-year cohort study", found that participants who used cannabis experienced greater pain, were not dealing well with their pain and had greater anxiety than those who did not use cannabis. The researchers also found no clear evidence that cannabis use reduced the use of prescribed opioids.
However, the researchers also found inconsistencies between their statistical evaluation and what the participants reported. Participants who used cannabis reported that the average effectiveness of cannabis against pain was seven out of a possible score of 10.
"Chronic pain not related to cancer is a complex problem, for most people it is little There is likely to be only one effective treatment, "said lead author Gabrielle Campbell in a UNSW Sydney press release. "In our study of people living with chronic non-cancer pain who were prescribed pharmaceutical opioids, despite reporting perceived benefits of cannabis use, we found no strong evidence that cannabis use reduced pain or opioid use. in the time".
were recruited through community pharmacies throughout Australia for the study of pain and opioids in treatment, which was observed in participants with opioids prescribed for chronic pain unrelated to cancer. The participants completed the initial interviews and followed up with telephone interviews or self-completed questionnaires annually for four years. Recruitment took place from August 13, 2012 to April 8, 2014, with 1,514 participants who completed the initial interviews and were included in the study from August 20, 2012 to April 14, 2014.  The most common types The study, led by the National Center for Drug and Alcohol Research (NDARC) at UNSW Sydney, was funded by the National Board of Health and Medical Research and the Australian Council of Medical and Health Research. government.
According to the researchers, "this is one of the longest and most detailed prospective studies of a community cohort of people with chronic non-cancer pain, which examines the effects of cannabis use on pain and the prescribed use of opioids." "
Although Australia legalized medical marijuana in 2016, the change did not actually affect the study, meaning that participants used mainly illegally produced cannabis.
Some experts expressed reservations about the study.
" This The study is certainly worrisome with respect to the efficacy of cannabis for pain unrelated to cancer, "Dr. Jordan Tishler, a Massachusetts area physician, president of the Association of Cannabis Specialists and CEO of inhaleMD, told Marijuana.com. "It was well designed and a reasonable number of subjects was observed for a reasonable period of time. However, this is a prospective cohort study that can show strong relationships but can not prove causality. In fact, in their discussion they comment on other studies, randomized controlled studies, the only type that can show causality, that have shown benefit for pain. His opinion is that these studies were too narrow in their inclusion criteria, a valid criticism, but not one that validates his own study more. "
Tishler added that although one of the main conclusions was that cannabis users had worse pain and felt more anxiety than non-users, it is possible, the researchers observed, that cannabis users had worse pain at the beginning. and, therefore, were interested in cannabis to help their opioids in addition to non-users.
"The authors point out that during most of the time during their study, cannabis was completely illegal in Australia" He said, "Not only does it mean we have no idea what kind of cannabis patients they were using, it also means, more importantly, that none of these patients was counseled and followed by a cannabis specialist." We know that, like all The other drugs, cannabis can be used incorrectly and can have negative results, only with careful dosing and monitoring can we reasonably expect a benefit in a large group. This study did not attempt to stratify patients according to their dose or regimen, which I hope would have shown a clear benefit for subgroups that were using cannabis in more moderate amounts. "
Tishler said he has seen medicinal cannabis benefits on his own practice, but the results may vary.
"Cannabis seems to work well for a variety of non-cancerous pains: inflammatory pain like [rheumatoid arthritis] or Crohn's, [as] and mechanical pain like osteoarthritis," he said. it is perfect. It does not seem to work for everyone, and there are risks and side effects like all medications. Some people tolerate it and do it well, others occasionally do not. In short, we have to consider cannabis as a drug in a dispassionate way so that we can use it properly for patients. "
Osteopathic doctor Michelle Weiner, specialist in pain management at Spine and Wellness Centers of America South, said that I am not impressed with the study and I find it difficult to refer when your daily clinical experience finds that cannabis is a safer and effective solution to decrease the use of opioids for pain.
"The author clarifies that 22 and 30 percent of the patients reported that they sometimes or regularly reduce their opioid medication when they use cannabis at the three-year and four-year follow-up respectively, "he said.
Dr. Blake Pearson, a practicing physician specializing in cannabinoid medicine in Ontario, Canada and founder of GreenlyMed.com, said that according to the design and methods of the study, a causal relationship Significant difference between cannabis use and its effects on chronic pain unrelated to cancer can not be established.
"This study did not investigate the modes of ingestion, the amount of cannabis in grams that was consumed, the formulation (amount and proportion of CBD or THC present) or the frequency of dosing per day," Pearson said. "Not only that, but none of the study participants was under medical supervision for cannabis therapy." At the time this study was conducted, medical cannabis was still illegal in Australia, so these participants used illegal marijuana from the street and would be considered "recreational users." This is important for several reasons, including that cannabis is used for recreational activities in general, the purposes do not contain CBD: the cannabinoid that is effective in relieving pain without causing deterioration. "
He said that more studies are essential.
"Until we have more prospective randomized controlled trials, the gold standard in medical research, we will continue to go around in circles with cannabis as a debate about medicine," he said. "To legitimize cannabis as a medicine and improve the access of patients from all over the world who could benefit, a higher quality research is essential."