TORONTO -- A new Canadian study has found that human-made synthetic cannabinoids, a class of prescription pills that contain synthetically-made chemicals found in marijuana, may be linked to an increase in negative respiratory health and even death among older adults with chronic obstructive pulmonary disease (COPD).
The study, conducted by researchers at St. Michael's Hospital of Unity Health Toronto, reported that perscription oral synthetic cannabinoid use is associated with a 64 per cent increase in death among older adults with COPD.
The study found that perscription oral synthetic cannabinoids can contribute to negative respiratory health events in people with COPD, including hospitalization and death, despite the medication being ingested orally.
Researchers said they also observed particularly worse health outcomes among patients with COPD who were using higher doses of oral cannabinoids.
COPD is a progressive lung disease that causes difficulty breathing and chronic productive coughing that produces phlegm, and can be associated with a variety of non-respiratory issues, including chronic muscle pain and insomnia, according to researchers.
Oral synthetic cannabinoids are often prescribed as an alternative to opioids to help treat some symptoms of COPD including pain, difficulty sleeping and breathlessness.
The findings were published Wednesday in the journal Thorax.
St. Michael's respirologist and lead author of the study Dr. Nicholas Vozoris said the findings have "significant clinical implications" as more physicians prescribe oral synthetic cannabinoids to patients with COPD.
"Cannabinoid drugs are being increasingly used by older adults with COPD, so it is important for patients and physicians to have a clear understanding of the side-effect profile of these drugs," Vozoris said in a press release.
Vozoris said older adults with COPD who use prescribed oral cannabinoids may be more susceptible to negative respiratory outcomes, as their immune systems are less robust.
"Older adults with COPD represent a group that would likely be more susceptible to cannabinoid-related respiratory side-effects, since older adults less efficiently break down drugs and hence, drug effects can linger in the body for longer -- and since individuals with COPD have pre-existing respiratory troubles and respiratory compromise," Vozoris said in the release.
The study looked at the health data of over 4,000 Ontarians aged 66 and older with COPD from 2006 to 2016. The data, made available by independent, non-profit research institute ICES, was split into two groups -- older adults with COPD who were new cannabinoid users and older adults with COPD who were not using cannabinoids.
The data showed particularly worse health outcomes among patients with COPD who were using higher doses of oral synthetic cannabinoids.
Compared to non-users, researchers found that new, higher-dose oral cannabinoid users had a 178 per cent relative increase in hospitalizations for COPD or pneumonia, and a 231 per cent relative increase in death.
Researchers also conducted a sub-analysis to explore what impact oral synthetic cannabinoid drugs compared to opioid drugs had on respiratory outcomes among older adults with COPD. The research team did not find evidence to support that cannabinoids were a safer choice over opioids.
While oral synthetic cannabinoid use was associated with greater adverse health outcomes among older adults with COPD, the study acknowledges that more research is needed.
Vozoris explained that the data does not mean that cannabinoid drugs should never be used among older adults with COPD, but that doctors need to consider the impacts before prescribing them.
"Our findings should be incorporated by patients and physicians into prescribing decision-making. Our results also highlight the importance of favouring lower over higher cannabinoid doses, when these drugs actually do need to be used," Vozoris said in the release.
