Cannabis legalization led to more hospital trips for cannabis poisoning among older adults, administrative data in Canada showed.
Emergency department (ED) visits for cannabis poisoning among older people in Ontario doubled after dried cannabis flowers were legalized for recreational use (adjusted incidence rate ratio [IRR] 2.00, 95% CI 1.29-3.10) and tripled after edible cannabis was legalized (adjusted IRR 3.08, 95% CI 2.04-4.65), reported Nathan Stall, MD, PhD, of the University of Toronto in Canada, and co-authors.
Many of these older ED patients also had cancer, alcohol use disorder, or dementia, Stall and colleagues reported in a research letter.
"While the design of our study limited us from determining whether poisonings were unintentional or intentional, we suspect both contributed to the harms we observed," Stall told . "Older adults are prone to unintentional poisonings because edible cannabis products are visually attractive and palatable and may be taken in error, being easily confused with non-cannabis food items," he suggested.
Older people also may be prone to adverse effects associated with intentional cannabis exposure, Stall said. "Contemporary cannabis is very potent; today's cannabis extracts contain as much as 30 times more THC than dried cannabis from the mid-1980s and early 1990s," he observed.
There are predictable age-related declines in how cannabis is metabolized, Stall continued. "Older adults also are more likely to take multiple prescription medications that can interact with cannabis, and may be more susceptible to the intoxicating effects of the drug because of underlying health conditions, sensory impairment, and cognitive decline," he said.
Nearly in the U.S. have used cannabis recently, according to Substance Abuse and Mental Health Services Administration (SAMHSA) surveys. Medical cannabis is reportedly well-tolerated in older patients and has provided relief in chronic pain, sleep, neuropathy, or anxiety in some studies, but less is known about recreational cannabis.
The analysis by Stall and colleagues "provides a cautionary tale of legalization of substances without adequate research, education, and counseling of users regarding adverse effects and safe usage, particularly in older adults," wrote Lona Mody, MD, MSc, of the University of Michigan in Ann Arbor, and Sharon Inouye, MD, MPH, of Hebrew SeniorLife in Boston, in an .
Some older adults may use cannabis to self-manage conditions like pain, nausea, or insomnia, Mody and Inouye pointed out. "Legalization of edible cannabis has increased access and provided a potential option for self-treatment that does not require communication with a clinician," they wrote. "When surveyed, nearly half of older adults state that they do not discuss their nonmedical cannabis use with their clinicians."
Stall and co-authors used Ontario Ministry of Health data to review ED visits for cannabis poisoning in older adults over three time spans: the pre-legalization period (January 2015 to September 2018); the first legalization period, when dried cannabis flowers could be sold (October 2018 to December 2019); and the second legalization period, which also allowed the sale of edible cannabis (January 2020 to December 2022).
Over 8 years, 2,322 ED visits for cannabis poisoning in older adults were recorded. Patients had a median age of 69.5 years, and most ED visits (55.2%) involved men. Overall, 38.5% of those with cannabis poisoning had cancer, 16.6% had concomitant alcohol intoxication, and 6.5% had dementia.
The analysis evaluated ED data only and may underestimate the magnitude of cannabis poisonings in older adults, Stall and co-authors acknowledged. Concurrent events, including the COVID-19 pandemic, also may have influenced outcomes.
"Edible cannabis products should include dosing information with specific guidance for older adults, and the geriatric therapeutic principle of 'start low and go slow' is particularly relevant," Stall said. "Clinicians should recognize that many older adults are using cannabis products, and have open and judgement-free conversations about its use."
Disclosures
Stall reported no conflicts of interest.
Co-authors reported relationships with the Public Health Agency of Canada, the Canadian Institute for Health Research, and private law firms for expert medicolegal opinions about drug safety and effectiveness.
Mody and Inouye are editors of JAMA Internal Medicine; they reported no conflicts of interest.
Primary Source
JAMA Internal Medicine
Stall NM, et al "Edible cannabis legalization and cannabis poisonings in older adults" JAMA Intern Med 2024; DOI: 10.1001/jamainternmed.2024.1331.
Secondary Source
JAMA Internal Medicine
Mody L, Inouye SK "Adverse consequences of legalization of edible cannabis in older adults" JAMA Intern Med 2024; DOI: 10.1001/jamainternmed.2024.1337.