Harvard Study Finds Cannabis Effective for Chronic Pain

By Pat Anson, PNN Editor

Long-term use of medical cannabis may be an effective treatment for chronic pain, according to a small study by researchers at Harvard Medical School and McLean Hospital in Boston.

Thirty-seven patients suffering from arthritis, joint pain, neuropathy and other chronic pain conditions were evaluated over a six-month period while ingesting cannabis products through smoking, vaporizing, edibles, oils and other methods. All of the patients were cannabis “naive” — meaning they had never used cannabis before or had abstained from use for at least a year prior to the study.

After six months of daily treatment with cannabis, patients reported significant improvements in their pain, sleep, mood, anxiety and quality of life. Their use of opioid pain medication declined by an average of 13% and 23% after 3 and 6 months of treatment, respectively, although not to a degree that was considered significant.

A control group of 9 pain patients that did not use cannabis did not have a similar pattern of improvement in pain or other symptoms. 

“This naturalistic study of medical cannabis (MC) patients with chronic pain provides preliminary evidence that ‘real world’ MC treatment may be a viable alternative or adjunctive treatment for a least some individuals with chronic pain,” wrote lead author Staci Gruber, PhD, Associate Professor of Psychiatry at Harvard Medical School. 

“As results also revealed that individual cannabinoids appear to exert unique effects on pain and comorbid symptoms, more research is needed to potentially optimize cannabinoid-based treatments for pain.”

Gruber and her colleagues say increased exposure to tetrahydrocannabinol (THC), the psychoactive ingredient in cannabis, appeared to be closely related to improvements in pain, while increased CBD exposure was related to improvements in mood, but not pain. Many patients reduced their use of THC as the study progressed.

“Interestingly, we have found that many patients aim to achieve symptom alleviation without experiencing the intoxicating effects of THC. Therefore, it is likely that patients are able to achieve adequate pain relief using lower doses of THC over time than initially utilized,” said Gruber, who heads the Marijuana Investigations for Neuroscientific Discovery (MIND) program at McLean Hospital.

Researchers say additional studies are needed to explore how THC and CBD modulate pain and other symptoms. Their findings are published in the journal Experimental and Clinical Psychopharmacology.  

While the findings are intriguing, the small number of patients involved in this and most other cannabis studies makes it hard to draw firm conclusions.  

Last month two professional pain societies – the International Association for the Study of Pain (IASP) and the Australian and New Zealand College of Anaesthetists -- released statements saying they could not endorse the use of cannabis to treat pain because there are no large, high-quality and unbiased clinical trials of cannabis as an analgesic.

Steep Decline in New Opioid Prescriptions

By Pat Anson, PNN Editor

The number of doctors writing new prescriptions for opioid pain medication has fallen by nearly a third in recent years, according to a large but limited study that documents a dramatic shift in opioid prescribing patterns in the U.S.

Researchers at Harvard Medical School studied health data for over 86 million patients insured by Blue Cross Blue Shield from 2012 to 2017, and found that first-time prescriptions for patients new to opioids – known as “opioid naïve” patients -- declined by 54 percent.

At the start of the study, 1.63% of Blue Cross Blue Shield patients were being treated with new opioid prescriptions. Five years later, only 0.75% were.

The study also found a shrinking pool of doctors willing to start opioid treatment. The number of doctors who prescribed opioids for opioid naive patients decreased by nearly 30 percent, from 114,043 to 80,462 providers.

The research findings, published in The New England Journal of Medicine, do not provide any context on the patients’ health conditions or the severity of their pain and injuries. As such, it is a data-mining study that provides no real information on the harms or benefits of opioids.

"The challenge we have in front of us is nothing short of intricate: Curbing the opioid epidemic while ensuring that we appropriately treat pain," lead investigator Nicole Maestas, PhD, an associate professor of health care policy at Harvard Medical School, said in a statement. "It's a question of balancing the justified use of potent pain medications against the risk for opioid misuse and abuse."

First-time prescriptions for opioids are usually used to treat short-term acute pain caused by trauma, accidents or surgery. They rarely result in long-term opioid use or addiction, but have become a major target for healthcare policymakers and anti-opioid activists. Several states have adopted regulations that limit the initial supply of opioids to 7 days or less.

While the number of doctors starting opioid therapy has fallen dramatically, Harvard researchers say many are still engaged in “high-risk prescribing” – which they defined as new prescriptions for more than 3 days’ supply or a daily dose that exceeds 50 morphine milligram equivalent (MME).

More than 115,000 of these “high-risk prescriptions” were written monthly for Blue Cross Blue Shield patients. Over 7,700 of the prescriptions exceeded 90 MME per day, a dose that researchers say puts patients at a substantially higher risk of an overdose. The study did not identify whether any of those high-dose patients experienced an overdose.

Opioid prescriptions in the U.S. have fallen sharply since their peak in 2010, but have yet to slow the rising tide of overdoses. Nearly 49,000 Americans died from opioid overdoses in 2017, over half of them due to illicit fentanyl and heroin, not prescription opioids.