Results from a double blinded, randomized, placebo-controlled, feasibility trial of melatonin for the treatment of delirium in older medical inpatients

Peter W Lange, Daniel I Clayton-Chubb, Rosie Watson, Andrea B Maier

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BACKGROUND: Delirium is common in elderly inpatients, causing distress, cognitive decline, and death. No known intervention improves the course of delirium; current treatments are symptomatic, and limited by lack of efficacy and adverse effects. There is an urgent need to find an effective treatment for delirium.

AIMS: Determine the feasibility of a trial of oral Melatonin 5mg nightly for 5 nights for the treatment of delirium in older medical inpatients, and determine the participants required to demonstrate a clinically and statistically significant decrease in severity of delirium in older medical inpatients treated with Melatonin.

METHODS: This was a double blinded, randomized controlled trial in general internal medicine units of a tertiary teaching hospital. Older (≥70 years) inpatients with Confusion Assessment Method (CAM) positive hyperactive or mixed delirium were suitable for inclusion. Subjects received Melatonin 5mg oral nightly for 5 nights or matching placebo. The primary outcome was the Memorial Delirium Assessment Scale (MDAS) administered daily.

RESULTS: No adverse effects occurred due to Melatonin. In the treatment group, the mean change in MDAS from baseline during treatment period was 2.5±5.0 points, in the placebo group, 2.1±4.1 points, a non-significant difference. A power calculation accounting for drop-out (31.0%), suggests 120 participants would be required to demonstrate with 90% power that melatonin 5mg reduces the severity of delirium by 3 points or more on MDAS.

CONCLUSIONS: A trial of the hypothesis that 5mg Melatonin nightly for 5 nights reduces delirium severity in older medical inpatients would require 120 patients, and is feasible. This article is protected by copyright. All rights reserved.

Original languageEnglish
JournalInternal Medicine Journal
Publication statusE-pub ahead of print - 27 Jan 2020


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This article is protected by copyright. All rights reserved.

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