Unused opioids remained common weeks after emergency department discharge
A Canadian multicenter cohort study found that unused prescription opioids were still sitting at home in most patients after emergency department discharge for acute pain, with storage practices that left many tablets accessible to others in the household. The pattern was visible early and persisted months later, despite the fact that these prescriptions were written for short-term pain after an acute visit rather than chronic use.
The study followed adults discharged from seven hospitals in Québec and Ontario with an opioid prescription for an acute pain condition. Participants were enrolled between May 2019 and January 2024 as part of the OPUM study, a prospective multicenter cohort, and were contacted at 2 weeks and 3 months after discharge. Among 2590 enrolled patients, 2047 completed the 2-week follow-up and 1835 completed the 3-month follow-up, giving the analysis a broad view of what happened to these prescriptions after patients left the emergency department.
Most patients still had pills left at 2 weeks
At the 2-week mark, 1521 of 1811 participants, or 84.0%, reported unused opioids. The proportion is striking because it means the large majority of prescriptions outlasted the immediate pain episode by at least some margin. In practical terms, many patients went home with more opioid tablets than they needed for the pain trajectory they actually experienced.
Baseline characteristics of those who completed 3-month follow-up help frame the cohort: mean age was 51.3 years, 51.6% were male, and mean pain intensity at triage was 7.1 out of 10. The study did not need an exotic population to generate this signal. It reflected everyday emergency care, where clinicians must decide how much opioid to prescribe before they can know how quickly an individual patient will improve.
The data point to a familiar problem in acute pain care: prescription size often exceeds actual consumption. When that happens across thousands of visits, the leftover medication burden accumulates quickly at the household level.
Storage practices left many tablets accessible at home
Storage conditions were not reassuring. Among 1525 participants assessed at 2 weeks, only 102, or 6.7%, said they kept their opioids in a locked area. Another 393 participants, or 25.8%, stored the medication out of reach of children or teenagers. Those numbers still leave a large fraction without a secure storage plan detailed enough to reduce diversion, accidental ingestion, or casual access by visitors or family members.
The issue is not abstract. Unused opioid tablets in a bathroom cabinet, kitchen drawer, or other unsecured location can become a risk long after the original pain episode has resolved. For households with children, adolescents, or people with substance use vulnerability, storage practice can determine whether leftover medication remains merely inconvenient or becomes a safety hazard.
By 3 months, most unused opioids were still kept at home
At 3 months, 926 of 1495 participants, or 61.9%, still reported unused opioids. The reason for keeping them was usually practical on the surface but clinically important underneath. More than half of those participants, 534 or 57.7%, held on to the medication for possible future pain. Another 262, or 28.3%, said they forgot or lacked time to return it.
Those answers reveal two different barriers. One is behavioral: people keep opioids because they may feel useful later, especially if they had significant pain during the initial episode. The other is logistical: even when patients do not plan to reuse the medication, disposal can slip down the list of priorities once the acute event has passed.
A short paragraph from the dataset carries the main safety message plainly: most leftover opioids did not leave the home.
Willingness to return medication was limited
Disposal intent was modest even when participants were asked directly. Only 614 of 1835 participants, or 33.5%, said they would voluntarily return opioids to the pharmacy if prompted. Even more concerning, 479 participants, or 26.1%, said they would not return them regardless of any incentive offered.
This finding matters because it suggests that passive advice alone is unlikely to solve the problem. A prescription handout or brief discharge warning may not be enough when patients perceive the medication as a reserve for future pain, or when they see disposal as a task with little immediate benefit. The response pattern also suggests that some patients are resistant to return efforts even if the system makes them easier.
For emergency clinicians, the study reinforces the need to think about the full medication life cycle at the moment of prescribing. The decision is not only about controlling pain for the next several days. It also shapes what remains in the home for weeks or months afterward.
Prescribing, education, and take-back access all need to work together
The findings support several practical steps. First, opioid prescriptions for acute pain should be tailored as closely as possible to expected need, so fewer unused tablets are created in the first place. Second, discharge counseling should include clear instructions about safe storage, since only a small minority reported locking the medication. Third, disposal pathways need to be simple, visible, and accessible if health systems expect patients to use them.
The study also raises a policy question that extends beyond the emergency department. If only one-third of patients say they would return leftover opioids even when prompted, then take-back programs must overcome inertia, inconvenience, and the mistaken idea that keeping the medication is harmless. Education alone may help, but the data suggest that education without structural access will not be enough.
This was a cohort study, not an interventional trial, so it cannot prove which strategy will most effectively reduce leftover opioids. It does show where the problem sits: in the gap between prescription amount, actual use, home storage, and the low likelihood of disposal. The next step is not to ask whether leftover opioids matter. The next step is to determine how much smaller prescriptions, stronger counseling, and easier take-back systems can change the numbers that this cohort made visible.