Beneficial effect of donepezil on obstructive sleep apnea: A double-blind, placebo-controlled clinical trial

Introduction/objectives: Previous publications have shown beneficial effects of cholinergic medication on obstructive sleep apnea (USA) in Alzheimer's disease (AD) patients. We hypothesized that cholinergic medication could also improve USA in non-AD patients. The present study evaluated the effects of donepezil on USA in non-AD patients. Methods: A randomized, double-blind, placebo-controlled study was conducted. The final sample consisted of 21 male patients with mild to severe USA and AHI >10 divided into two groups, a donepezil-treated group (n = 11) and a placebo-treated group (n = 10). The dosage was one tablet/day (5 mg) for the first two weeks and two tablets/day (10 mg) for the last two weeks. Polysomnography and sleepiness evaluations were performed at baseline and after one month of treatment. Groups were compared using two-way ANOVA for repeated measures with treatment-group and treatment-time as the main factors and time-treatment as an interaction effect. Results: Considering the effect of the interaction with time-treatment, there was a significant improvement in the obstructive apnea/hypopnea index, desaturation index, percentage of time with O-2 saturation <= 3% lower than baseline, lowest oxygen saturation, and the Epworth Sleepiness Scale (ESS) scores with donepezil treatment (p < 0.05). Sleep efficiency significantly decreased (p < 0.01). Conclusions: Donepezil treatment improved obstructive sleep apnea index, oxygen saturation, and sleepiness in parallel with a reduction in sleep efficiency. Our findings support the concept that cholinergic transmission may influence breathing regulation in USA patients. (C) 2011 Elsevier B.V. All rights reserved.