Synthetic THC is Associated With Increased Mortality in Older Lung Disease Patients, Study Finds
The use of prescription cannabinoids by older adults with chronic obstructive pulmonary disease (COPD) may lead to an elevated risk of developing adverse respiratory health effects, a new study has found.
The findings, published in the respiratory medicine journal Thorax, come from a new retrospective study of patient data from 2006 to 2016, led by scientists from St. Michael’s Hospital of Unity Health, Toronto.
Despite the risks identified by the study, the researchers say they still believe the cannabinoid drugs, which include nabilone and dronabinol, can be useful treatments. Prescribers and patients, the researchers say, should just keep the risk factors in mind when deciding on an appropriate course of treatment.
Higher doses linked to worse outcomes
The researchers conducted a retrospective study looking at patient data collected in Ontario between 2006 and 2016.
They identified just over 2,000 patients over the age of 66 with COPD – a progressive lung disease that causes long-term breathing problems as well as non-respiratory complaints such as chronic pain or insomnia – who had also been prescribed either nabilone and dronabinol within the past year. These patients were matched to a control patient who had not been prescribed cannabinoids, and the data for both was analyzed to uncover any variation in health outcomes.
Both dronabinol and nabilone are synthetic forms of THC, although nabilone can be more potent.
Overall, there was no difference in the rate of hospitalizations for COPD or pneumonia between the COPD patients who were on cannabinoid medications and the control group. However, there was a relative increase in the all-cause mortality rate for those new cannabinoid users of around 64 percent.
There was a particularly large discrepancy observed between those on high doses of cannabinoid medications versus the control group. Compared to non-users, the patients on high-dose cannabinoid prescriptions had a 178 percent relative increase in hospitalizations, and a 231 percent relative increase in all-cause deaths.
“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,” Dr Nicholas Vozoris, the study’s lead author and associate scientist at St. Michael’s Hospital, explained in a press statement.
What does this mean for prescription cannabinoid use?
The researchers say that their findings may have significant clinical implications, as physicians are now more commonly able to prescribe cannabinoid medications to COPD patients to treat complaints such as chronic muscle pain, sleeping problems, and shortness of breath. As a result, it is important to properly examine the impact of cannabinoid treatments on individuals with respiratory health conditions.
“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,” says Dr Vozoris, who is also a scientist at the health research and informatics non-profit ICES, formerly the Institute for Clinical Evaluative Sciences.
“Our study results do not mean that cannabinoid drugs should be never used among older adults with COPD. Rather, our findings should be incorporated by patients and physicians into prescribing decision-making. Our results also highlight the importance of favoring lower over higher cannabinoid doses, when these drugs actually do need to be used.”
The researchers also carried out a sub-analysis aimed at exploring the impact of opioid drugs on respiratory health outcomes, in order to compare this against the effects of the cannabinoid treatments.
Increasingly, cannabinoid treatments are being tipped as an alternative to opioids for chronic conditions as cannabinoids carry a much lower risk of addiction and overdose, and so the researchers felt it necessary to compare the two treatments. However, they found no significant evidence supporting or rejecting cannabinoids as a safer choice with respect to respiratory health outcomes.