Daily cannabis use lowers odds of using illicit opioids among people who have chronic pain

Science Daily/University of British Columbia

For those using illicit opioids to manage their chronic pain, cannabis may be a beneficial -- and a less dangerous -- alternative, according to new research from the BC Centre on Substance Use (BCCSU).

Researchers from the BCCSU and University of British Columbia (UBC) interviewed more than 1,100 people at highest risk of opioid overdose in Vancouver between 2014 and 2017 who reported substance use and major or chronic pain. They found that daily cannabis use was associated with significantly lower odds of daily illicit opioid use, suggesting people are replacing opioids with cannabis to manage their pain.

The study was published today in a special issue of PLOS Medicine on substance dependence.

"These findings, in combination with past research, again demonstrate that people are using cannabis to help manage many different conditions, including pain. And in some cases, they're using cannabis in place of opioids," says senior author Dr. M-J Milloy, a research scientist at BCCSU and the Canopy Growth professor of cannabis science at UBC. "In the midst of an ongoing public health emergency caused by opioid overdose deaths, the results suggest that increasing access to cannabis for therapeutic purposes could help curb overdose risk associated with illicit opioid use."

Results from a statistical model showed that people who used cannabis every day had nearly 50 per cent lower odds of using illicit opioids every day compared to cannabis non-users, whereas people who reported occasional use of cannabis were neither more nor less likely than non-users to use illicit opioids on a daily basis.

Researchers further found that there may be an intentional therapeutic element associated with at least daily cannabis use. For instance, daily users were significantly more likely than occasional users to report a number of therapeutic uses of cannabis, including addressing pain, stress, nausea, mental health, and symptoms of HIV or side effects of HIV antiretroviral therapy, or improving sleep.

The findings suggest that some people who use drugs and who are experiencing pain might be using cannabis as an ad-hoc, self-directed strategy to reduce the frequency of opioid use.

"These findings point to a need to design formal clinical evaluations of cannabis-based strategies for pain management, opioid use disorder treatment supports, and wider harm reduction initiatives," says Stephanie Lake, a PhD candidate at UBC's school of population and public health, and the lead author of the study.

Milloy is currently planning controlled trials to evaluate whether cannabis could help people with opioid use disorder stay on their treatment and serve as a substitute to opioid use.

https://www.sciencedaily.com/releases/2019/11/191119141233.htm

Combining opioids and marijuana may be advantageous for pain sufferers

Study suggests using the two drugs together could reduce risk of dependency without causing cognitive problems

April 9, 2019

Science Daily/Experimental Biology

Researchers report combining cannabinoids with morphine did not significantly increase impulsivity or memory impairment in a study conducted in rhesus monkeys. The findings suggest using opioids and marijuana together could offer a safe way to cut opioid dosage among patients suffering from pain and thereby reduce their risk of becoming addicted to opioids.

"These data provide additional evidence supporting the notion that opioid-cannabinoid mixtures that are effective for treating pain do not have greater, and in some cases have less, adverse effects compared with larger doses of each drug alone," said Vanessa Minervini, PhD, a postdoctoral fellow at the University of Texas Health Science Center at San Antonio.

Minervini will present the research at the American Society for Pharmacology and Experimental Therapeutics annual meeting during the 2019 Experimental Biology meeting, held April 6-9 in Orlando, Fla.

Previous studies have suggested the cannabinoids in marijuana enhance some of the pain-relieving effects of opioid drugs but do not enhance effects related to addiction and overdose. However, both drugs individually are known to slightly impair cognition, leading to a concern that such side effects could be amplified if opioids and marijuana are used together. Researchers say the new study offers encouraging evidence this is not the case.

The research comes amid a national opioid abuse crisis in which many addictions start with opioids prescribed for pain. At the same time, marijuana use is on the rise as more states legalize the drug for medical or recreational use.

"The current opioid epidemic underscores the need for safe and effective pharmacotherapies for treating pain," said Minervini. "Combining opioid receptor agonists with drugs that relieve pain through actions at non-opioid mechanisms (for example, cannabinoid receptors) could be a useful strategy for reducing the dose of opioid needed to achieve pain relief."

The researchers gave several monkeys moderate doses of morphine and CP55940, a synthetic drug that mimics the activity of the tetrahydrocannabinol (THC) naturally found in marijuana. They assessed impulsivity and memory with tests involving touchscreens and treats. The results showed each drug impeded performance and that giving the monkeys both drugs together had a lower effect on performance than either drug alone.

While clinical trials would need to be conducted to confirm whether these results translate to humans, monkeys tend to process drugs similarly to humans and are considered a good model for cognition.

https://www.sciencedaily.com/releases/2019/04/190409135930.htm