Preventive effects of active Protocol-Based Pharmacotherapy Management for delirium in general wards of emergency department (aPBPM trial): study protocol for a single-center, randomized controlled trial {1a}

Background Delirium is a frequent complication in older patients admitted to emergency wards, leading to prolonged hospitalization and increased mortality. Although multicomponent interventions are recommended, the evidence for pharmacological prevention remains inconsistent. Protocol-Based Pharmacotherapy Management (PBPM) allows pharmacists to actively manage medications according to a pre-agreed protocol. This study aims to evaluate the efficacy and safety of an “Active PBPM” strategy for delirium prevention compared with that via a standard “Passive PBPM” strategy in elderly emergency patients. Methods This single-center, open-label, randomized controlled trial will target patients aged ≥65 years admitted to the general ward of the Department of Primary Care and Emergency Medicine from the emergency room. Eligible patients must have at least one risk factor (e.g., cognitive dysfunction, central nervous system disease). The patients will be randomized (1:1) into either the Active or Passive PBPM group. In the Active PBPM group, pharmacists will intervene to administer prophylactic medication for 3 days, starting on admission day 1. Patients capable of oral intake will receive ramelteon (8 mg) and lemborexant (5 mg) at bedtime. Patients unable to take oral medication will receive a blonanserin patch (20 mg) applied overnight (19:00–06:00). In the Passive PBPM group, pharmacological intervention will be performed only if insomnia occurs. The primary outcome will be the incidence of delirium diagnosed by a psychiatrist based on the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition criteria, within the first 3 days. The secondary outcomes include delirium severity (Delirium Rating Scale-Revised-98), assessed by trained nurses, and safety. Discussion This study will determine whether pharmacist-led proactive pharmacological intervention (Active PBPM) reduces the incidence of delirium in high-risk older patients in acute care settings. The findings may establish a new standard of care for the prevention of delirium in emergency medicine. Trial registration Japan Registry of Clinical Trials (jRCT) jRCTs051220122.