A randomized controlled trial of quetiapine versus placebo in the treatment of delirium☆

Abstract 

Background

Delirium is a commonly occurring complex neuropsychiatric disorder. Evidence for its treatment based on randomized controlled trials (RCTs) is poor.

Aims

To determine the efficacy and acceptability of quetiapine in the treatment of delirium.

Method

A double-blind, RCT was conducted. A total of 42 patients were randomized to quetiapine or a placebo group. The primary outcome measure was the Delirium Rating Scale Revised 98. Other scales used were the Brief Psychiatric Rating Scale, Mini-Mental State Examination and Clinical Global Improvement. In order to account for missing data, a nonlinear mixed-effects model was used to estimate the difference between the two groups.

Results

The quetiapine group improved more rapidly than the placebo group. Specifically, the quetiapine group recovered 82.7% faster (S.E. 37.1%, P=.026) than the placebo group in terms of DRS-R-98 severity score. In terms of the DRS-R-98 noncognitive subscale, the quetiapine group improved 57.7% faster (S.E. 29.2%, P=.048) than the placebo group.

Conclusions

Quetiapine has the potential to more quickly reduce the severity of noncognitive aspects of delirium. This study was underpowered for treatment comparisons at specific points in time but nonetheless detected significant differences when analyzing the whole study period. While it is not possible to draw definitive conclusions, further larger studies exploring the use of quetiapine in other delirium populations seem justified. Larger increments in the dose of quetiapine may yield even stronger results.

Keywords: Delirium, RCT, Randomized Control Trial, Quetiapine, Acute Confusion, Dementia and delirium, Atypical antipsychotics, Non-linear mixed-effects model, DRS-R-98