Storage and Disposal of Unused Prescription Opioids for Acute Pain After Emergency Department Discharge.

Importance: Opioid misuse is a major public health concern, and unused prescription opioids can contribute to this problem. Objective: To estimate the proportion of unused opioids among patients discharged from the emergency department (ED) for acute pain, evaluate opioid storage and disposal practices, and identify factors that may motivate patients to return unused opioids. Design, Setting, and Participants: This cohort study, which was a preplanned substudy of a Canadian multicenter prospective cohort study (Quantity of Opioids for Acute Pain and Limit Unused Medication Group [OPUM] study, with recruitment beginning in May 2019 and follow-up ending in January 2024), included consecutive patients aged 18 years or older discharged from the EDs of 7 hospitals in Québec and Ontario with an opioid prescription for an acute pain condition. Participants were followed up at 2 weeks and 3 months. Exposure: Opioid prescription for acute pain at ED discharge. Main Outcomes and Measures: The main outcomes were the proportion of participants with unused opioids at 2 weeks and 3 months after ED discharge, opioid storage practices at 2 weeks, and opioid disposal practices at 3 months. Results: Of 2590 enrolled participants in the cohort, 2047 (79.0%) completed the 2-week follow-up and 1835 (70.8%) completed the 3-month follow-up. Among participants who completed the 3-month follow-up, mean (SD) age was 51.3 (15.4) years, 947 (51.6%) were male, and mean pain intensity score at triage was 7.1 (2.3) out of 10. At 2 weeks, 1521 of 1811 participants (84.0%; 95% CI, 82.2%-85.6%) reported unused opioids; 102 of 1525 (6.7%; 95% CI, 5.5%-8.1%) stored their opioids in a locked area and 393 of 1525 (25.8%; 95% CI, 23.6%-28.0%) out of reach of children or teenagers. At 3 months, 926 of 1495 (61.9%; 95% CI, 59.4%-64.4%) reported unused opioids, kept mostly for possible future pain (534 [57.7%; 95% CI, 54.4%-60.9%]) or because participants forgot or lacked time to return them (262 [28.3%; 95% CI, 25.4%-31.3%]). Only 614 of 1835 participants (33.5%; 95% CI, 31.3%-35.7%) indicated they would voluntarily return opioids to the pharmacy if prompted, while 479 (26.1%; 95% CI, 24.1%-28.2%) would not return them regardless of incentive offered. Conclusions and Relevance: In this cohort study, 3 months after their ED visit, many participants kept unused prescription opioids at home under suboptimal storage conditions; only one-third were willing to return their opioids to a pharmacy, while more than one-fourth were not. These findings support tailoring opioid prescriptions to individual patient needs to reduce unused medication, alongside strengthening take-back networks and enhancing patient education on safe use, storage, and disposal of opioids.