Importance: Medication-related events (MREs) are a frequent cause of emergency department (ED) visits and patient harm.Objective: To assess the efficacy of a pharmacist-led transition of care program in reducing ED visits related to the same MRE at 6 months compared with usual care.Design, Setting, and Participants: This prospective, open-label, parallel-group randomized clinical trial was conducted from November 2018 to July 2021 at the ED of Montpellier University Hospital, Montpellier, France, with a 6-month follow-up period. Adult patients with an MRE detected at ED admission were included. MREs included adverse drug events with or without misuse and medication nonadherence with unfavorable clinical evolution. End points were assessed blindly from the randomization arm. Data were analyzed from January 2022 to March 2024.Intervention: Participants were randomized to a pharmacist-led transition of care program or usual care. Usual care included the ED pharmacist carrying out a medication history. In the transition of care group, ED pharmacists additionally made a postdischarge telephone call to the general practitioner (GP) and community pharmacist, along with a letter, notifying them about MRE type, suspected medication, and management recommendations.Main Outcomes and Measures: The primary outcome was the proportion of patients with an ED visit for the same MRE at 6 months (same symptom and medication involved). Secondary outcomes included proportions of all-cause and MRE-related ED visits, hospitalizations, deaths, and medical office visits.Results: Among 330 patients analyzed, 187 (56.7%) were female, the median (IQR) age was 71 (50-83) years, and the median (IQR) home medications count was 6 (3-10). A total of 167 patients were randomized to the transition of care group and 163 to the control group. At 6 months, fewer participants in the transition of care group had ED visits related to the same MRE (5 [3.0%] vs 36 [22.1%]; risk difference [RD], −19.1 percentage points; 95% CI, −26.0 to −12.2; P < .001), all-cause ED visits (35 [21.0%] vs 57 [35.0%]; RD, −14.0 percentage points; 95% CI, −23.6 to −4.4), hospitalization related to the same MRE (3 [1.8%] vs 29 [17.8%]; RD, −16.0 percentage points; 95% CI, −22.2 to −9.8), and more GP office visits (88 of 158 [55.7%] vs 26 of 146 [17.8%]; RD, 37.9 percentage points; 95% CI, 28.0 to 47.8) and specialist office visits (67 of 158 [42.4%] vs 35 of 146 [24.0%]; RD, 18.4 percentage points; 95% CI, 8.1 to 28.8) related to the same MRE. All-cause hospitalization and death were similar between groups.Conclusions and Relevance: In this randomized clinical trial, a pharmacist-led transitional care intervention in the ED among patients with MRE significantly reduced ED visits and hospitalizations for the same MRE. If replicated in subsequent trials, this strategy offers a novel approach for reducing drug-related harms.Trial Registration: ClinicalTrials.gov Identifier: NCT03725046

Objectives: Adverse drug events (ADEs) are a major public health issue in hospitals. They are difficult to detect because of incomplete or unavailable medication history. In this study, we aimed to assess the rate and characteristics of ADEs identified by pharmacists in an emergency department (ED) to identify factors associated with ADEs. Methods: In this prospective observational study, we included consecutive adult patients presenting to the ED of a French 2600-bed tertiary care university hospital from November 2011 to April 2015. Clinical pharmacists conducted structured interviews and collected the medication history to detect ADEs (i.e., injuries resulting directly or indirectly from adverse drug reactions and noncompliance to medication prescriptions). Unsure ADE cases were reviewed by an expert committee. Relations between patient characteristics, type of ED visit, and ADE risk were analyzed using logistic regression. Results: Among the 8275 included patients, 1299 (15.7%) presented to the ED with an ADE. The major ADE symptoms were bleeding, endocrine problems, and neurologic disorders. Moreover, ADEs led to the ED visit, hospitalization, and death in 87%, 49.3%, and 2.2% of cases, respectively. Adverse drug event risk was independently associated with male sex, ED visit for neurological symptoms, visit to the ED critical care unit, or ED short stay hospitalization unit, use of blood, anti-infective, antineoplastic, and immunomodulating drugs. Conclusions: This study improves the knowledge about ADE characteristics and on the patients at risk of ADE. This could help ED teams to better identify and manage ADEs and to improve treatment quality and safety.