Canadian researchers have found the oral synthetic cannabinoids nabilone and dronabinol contribute to negative respiratory health events, including death, in older people with chronic obstructive pulmonary disease (COPD).

COPD covers two types of chronic diseases — namely emphysema chronic bronchitis — where the lung’s airways become swollen and partly blocked, reports The Lung Association. “COPD gets worse over time. It cannot be cured, but it can be treated and managed.”

Even with the medications, which contain synthetically made chemicals found in cannabis, being ingested orally, the study published in Thorax found that using cannabinoids was associated with a 64 per cent increase in death among older adults with COPD.

Led by St. Michael’s Hospital of Unity Health Toronto, researchers looked at Ontario health administrative data from 2006 to 2016 involving people 66 and older. These 4,000 people, which excluded patients with malignancy and those receiving palliative care, was split into two groups: older adults with COPD who were new cannabinoid users (had been dispensed nabilone or dronabinol, but not within the last year) and older COPD sufferers not using cannabinoids.

Not only were associated deaths greater, researchers determined that so too were hospitalizations, notes the study, the first published data regarding the impact of cannabinoids on the respiratory health of people with COPD.

“Our study results do not mean that cannabinoid drugs should be never used among older adults with COPD,” Dr. Nicholas Vozoris, the study’s lead author and a respirologist at St. Michael’s Hospital, notes in a statement from St. Michael’s Hospital in Toronto. “Rather, our findings should be incorporated by patients and physicians into prescribing decision-making,” says Dr. Vozoris.

Higher doses of cannabinoids were associated with poorer health outcomes. / Photo: magicmine / iStock / Getty Images Plus

Additionally, higher doses of cannabinoids were associated with poorer health outcomes. “Compared to non-users, new higher-dose cannabinoid users had a 178 per cent relative increase in hospitalizations for COPD or pneumonia, and a 231 per cent relative increase in all-cause death,” the statement notes.

Results, Dr. Vozoris says, “highlight the importance of favouring lower over higher cannabinoid doses, when these drugs actually do need to be used.”

Study authors conclude that findings should be considered in decisions to use cannabinoids among older adults with COPD.

“Older adults with COPD represent a group that would likely be more susceptible to cannabinoid-related respiratory side-effects.” / Photo: Getty Images Getty Images

This is particularly the case “ as more physicians prescribe cannabinoids to patients with COPD to treat chronic muscle pain, difficulty sleeping and breathlessness,” notes the hospital statement.

“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,” explains Dr. Vozoris.

Researchers also carried out a sub-analysis exploring the impact that cannabinoid drugs versus 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 for older adults with COPD in so far as respiratory health outcomes,” the statement notes.

Another study involving Dr. Vozoris, published in the European Respiratory Journal, found that opioid use, and in particular generally more potent opioid-only agents, “was associated with increased risk for adverse respiratory outcomes, including respiratory-related mortality, among older adults with COPD.”