Comparison of Two Doses of Prophylactic Melatonin on Incidence of Delirium in Intensive Care Unit Patients: A Randomized Controlled Trial

Background and aims: Delirium is a frequent and serious complication in critically ill patients, contributing to prolonged mechanical ventilation, extended intensive care unit (ICU) stays, and increased mortality. Disruption of circadian rhythms plays a key role in its pathogenesis. Melatonin, a neurohormone with chronobiotic and antioxidant properties, may help prevent ICU delirium, though the optimal dose remains uncertain. Patients and methods: This prospective, randomized, interventional study enrolled 120 adult ICU patients, randomized to receive either 3 mg (group A) or 6 mg (group B) oral melatonin nightly for at least 5 days. Baseline parameters were comparable between groups. Delirium incidence was assessed twice daily using the confusion assessment method for the ICU (CAM-ICU). Secondary outcomes included the timing of delirium onset, adverse effects, ICU stay, and mortality. Results: = 0.044), indicating a significant reduction with 6 mg of melatonin. The mean (SD) day of delirium onset and ICU length of stay were comparable between groups. Daytime somnolence was mild and similar across groups. Conclusions: Prophylactic administration of 6 mg of oral melatonin significantly reduced ICU delirium incidence compared with 3 mg, without added adverse effects. Higher-dose melatonin appears safe and more effective for delirium prevention in critically ill adults. How to cite this article: Kumar PA, Chawla K, Kohli S, Singh R. Comparison of Two Doses of Prophylactic Melatonin on Incidence of Delirium in Intensive Care Unit Patients: A Randomized Controlled Trial. Indian J Crit Care Med 2026;30(4):319-323.