Amnestic sleep-related eating disorder associated with zolpidem

Abstract

Objective: To describe the association of amnestic nocturnal eating behavior with use of zolpidem for insomnia.

Background: Sleep-related eating disorder is increasingly recognized in relationship to other diagnosable sleep disorders. Many of these disorders, like restless legs syndrome (RLS), give rise to complaints of insomnia. Zolpidem is the most commonly prescribed drug for insomnia complaints, and although it has sometimes been associated with side effects of transient amnesia and sleep walking, an association with sleep-related eating has not been previously emphasized.

Methods: Consecutive case series of five patients who were using zolpidem and evaluated with nocturnal eating behaviors.

Results: We evaluated five patients over 11 months with problematic amnestic nocturnal eating associated with zolpidem used for complaints of insomnia. All five patients had RLS, three had obstructive sleep apnea syndrome, two had sleep walking, and one had psychophysiologic insomnia. With discontinuation of zolpidem and effective treatment of their sleep disorders, nocturnal eating resolved.

Conclusions: Zolpidem, at least in patients with underlying sleep disorders that cause frequent arousals, may cause or augment sleep-related eating behavior. This report demonstrates the importance of arriving at a specific diagnosis for insomnia complaints, and alerts the sleep practitioner to this unusual side effect of zolpidem.

Introduction

Sleep-related eating syndromes comprise a spectrum of abnormal behaviors combining features of sleep and eating disorders (Table 1). Although first described four decades ago as ‘night-eating syndrome’ (NES) [1], more detailed observations have been published only in the last decade [2], [3], [4]. Sleep-related eating disorder (SRED) is characterized by partial arousals from sleep to ingest food, usually within the first 3 h after sleep onset [2]. Patients afflicted may describe an ‘automatic’ inclination to eat and a perceived inability to return to sleep without eating. Ingested substances can be ordinary, but often are highly caloric, and can be unusual. This behavior can lead to morning bloating, guilt, embarrassment, or to difficulty with perceived or actual weight control. Patients are totally or partially amnestic for up to half of eating episodes [4]. Amnestic eating and ingestion of unusual substances have drawn particular attention to these irregular behaviors, both in clinical and lay publications. In some series, the majority of patients are found to have restless legs syndrome (RLS), periodic limb movement disorder (PLMD), or obstructive sleep apnea syndrome (OSA) [2]. In one series, the majority of patients were taking psychotropic medications at the time of evaluation [4].

We report the onset or worsening of amnestic nocturnal eating behavior when zolpidem therapy was begun for insomnia, and the subsequent resolution of eating behavior with discontinuation of zolpidem and treatment of underlying intrinsic sleep disorders. These observations extend previous reports of amnestic complications and sleepwalking with zolpidem, describe an association of zolpidem with nocturnal eating, and emphasize the importance of accurate diagnoses in dealing with abnormal sleep behaviors.