BackgroundAdverse drug events (ADE) represent one of the main causes of admission to emergency department (ED). Their detection, documentation, and reporting are essential to avoid readmission.We hypothesize that a pharmacist-initiated multidisciplinary transition of care program combining ED pharmacist contribution and medications’ data transfer between inpatient and outpatient caregivers will reduce emergency visits related to ADEMethod/designThis is a prospective, open-label, randomized controlled trial. The primary aim of the study is 6-month ED readmission related to the same ADE. Three hundred forty-six adult patients with an ADE detected by a binomial pharmacist-physician will be recruited from the ED of an University Hospital and will be randomized in two groups: [1] experimental group (multidisciplinary transition of care program and medications’ data transfer between inpatient and outpatient caregivers) and [2] control group (usual care). Patients will be followed up over a period of 6 months. Endpoints will be carried out blindly of the randomization arm. The primary endpoint is the rate of patients who had at least one readmission in the ED for the same reason at 6 months (data collected during a phone call with the patient and the general practitioner). Trials registered NCT03725046.DiscussionThe trial results will have implications for the role of the clinical pharmacist in an emergency department. If successful, the intervention could be considered for implementation across other hospitals.Trial registrationClinicalTrials.govNCT03725046. Registered on 30 October 2018