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

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.

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.

Delirium occurred in 55.0% of patients in group A and 36.7% in group B (χ² = 4.062, p = 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.

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.

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.