Dapagliflozin Versus Metformin for the Management of Antipsychotic-Induced Weight Gain: A Pragmatic Pilot Randomized Controlled Trial

This is an open-label, pragmatic, parallel-group pilot randomized controlled trial comparing dapagliflozin with metformin for the management of antipsychotic-induced weight gain. The study will be conducted at the Department of Behavioral Medicine, Sultan Qaboos University Hospital, University Medical City, Muscat, Oman. Antipsychotic-induced weight gain is a common and clinically important adverse effect of antipsychotic treatment. It may contribute to reduced treatment adherence, poorer quality of life, and increased cardiometabolic risk. Metformin is commonly used to manage antipsychotic-associated weight gain, but its use may be limited by gastrointestinal adverse effects, dose titration, and pill burden. Dapagliflozin, a sodium-glucose cotransporter 2 inhibitor, has demonstrated weight-reducing and metabolic benefits in other clinical populations, but its role in antipsychotic-induced weight gain remains insufficiently studied. Participants will be randomized in a 1:1 ratio to receive either dapagliflozin plus a common lifestyle program or metformin plus a common lifestyle program. The trial will use a pragmatic PROBE-style design, with open-label treatment allocation and blinded outcome assessment and statistical analysis where feasible. Randomization will use a computer-generated sequence with allocation concealment. The study is designed as a pilot trial to assess feasibility, tolerability, adherence, safety, and preliminary estimates of treatment effect to inform a future definitive trial. Standardized procedures will be used for participant follow-up, medication review, safety monitoring, and data collection. Adverse events and treatment tolerability will be monitored throughout the study, and serious adverse events will be reported according to institutional and ethics committee procedures. Data will be collected by trained study personnel and entered into an electronic database with procedures to support completeness and accuracy. Analyses will be primarily descriptive and exploratory, consistent with the pilot nature of the trial, and will be used to refine assumptions for a future larger randomized controlled trial.