Effects of Daytime Eszopiclone Administration in Shift Workers

Not Applicable

Completed

Conditions: Shift-Work Sleep Disorder

Interventions: Drug: eszopiclone
Drug: matching placebo

Registration Number: NCT00900159

Lead Sponsor: Brigham and Women's Hospital

Brief Summary: The purpose of this study is to test the effects of eszopiclone on daytime sleep and overnight wakefulness in shift workers.

Detailed Description: The current study seeks to extend the currently available treatments for SWSD by addressing the putative root cause of the problem-the inability of night-shift workers with or without SWSD- to obtain adequate daytime sleep in the face of the circadian drive for alertness that increases across the biological day. Even healthy, young subjects who are sleep-deprived overnight exhibit daytime sleep marked by frequent awakenings and low sleep efficiency, less slow-wave sleep, and altered sleep architecture, e.g. earlier predominance of REM sleep. Many night-workers routinely report 3-6 hours of habitual sleep duration for daytime sleep. Pharmacological interventions to decrease awakenings and improve total sleep time during daytime sleep could improve subsequent alertness during a night shift. Improving the wakefulness of night-shift workers over the nighttime could result in substantial benefits for the individual workers, improve workplace productivity and safety, and improve public health.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 24

Inclusion Criteria

Age 20-50 (men or women)
Current shift worker (for at least 3 months, at least 5 overnights/month and 3 consecutive)
A willingness and ability to comply with study procedures
If of child-bearing potential, using a medically-accepted method of birth control, including abstinence, barrier method with spermicide, steroidal contraceptive (oral, transdermal, implanted, or injected) in conjunction with a barrier method, or intrauterine device [IUD]).

Exclusion Criteria

Current diagnosis of DSM-IV Axis I disorder (other than insomnia)
Regular treatment (>1time/wk) with CNS-active medication within 1 month of first inpatient visit
Uncontrolled medical illness that would interfere with participation in the study
BMI>32 or < 19.8 kg/m2
Current symptoms or diagnosis of any moderate to severe sleep disorder other than SWSD
Periodic Leg Movement of Sleep Index (PLMSi)>20/hr of sleep or Respiratory Desaturation Index (RDI)>15 on polysomnography (PSG)
Current alcohol or drug dependence/abuse
Menopausal or peri-menopausal symptoms that disrupt sleep
Pregnant, lactating, or planning to become pregnant
Current smoking of more than 10 cigarettes per day
Current use of over the counter sleep aids such as Benadryl or melatonin

Study & Design

Study Type: INTERVENTIONAL

Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
matching placebo	matching placebo	Treatment with matching placebo
eszopiclone	eszopiclone	Treatment with eszopiclone
matching placebo	eszopiclone	Treatment with matching placebo

Primary Outcome Measures

Name	Time	Method
Nighttime Wakefulness Assessed by Mean Sleep Latency Across 4 Maintenance of Wakefulness Tests	On each treatment, after an 8.5 hour daytime sleep period following at least 3 consecutive night shifts	Participants underwent four Maintenance of Wakefulness Tests (MWT) at 2-hour intervals during the simulated night shift starting 5 hours after wake time. MWT range from 0 to 40 minutes, where shorter times to fall asleep represent greater sleepiness (worse). MWT tests are averaged, for a mean in minutes.

Secondary Outcome Measures

Name	Time	Method
Objective Vigilance Task Performance	On each treatment, after an 8.5 hour daytime sleep period following at least 3 consecutive night shifts	A computer-based Flanker Task elicits responses to an incongruent pairing of stimuli measured as reaction time, in milliseconds. The Flanker task tests response inhibition, or the participants suppression of an unwanted response. A target stimulus (symbol) is "flanked" by non-target stimuli (symbols) that are the same as the target stimulus, opposite of the target stimulus, or neutral with respect to the target stimulus. The task is intended to assess the ability to maintain "selective attention" in the presence of distractors.
Sleep-dependent Memory Consolidation	On each treatment, after an 8.5 hour daytime sleep period following at least 3 consecutive night shifts	A computer-based Word-pair tasks is the number of words recalled after sleep from a list of words shown prior to going to sleep.
EEG-recorded Sleep Efficiency	On each treatment, during an 8.5-hr daytime sleep episode following at least 3 consecutive night shifts	Polysomnographic recordings of daytime sleep were made at sleep screen (8.5hr) and during daytime sleep episodes of 8.5 hours of duration during treatment visits. Sleep efficiency is calculated based on the time the participant spent in bed and the actual time the participant slept.
Subjective Sleepiness and Performance	On each treatment, after an 8.5-hr daytime sleep episode following at least 3 consecutive night shifts	The Karolinska Sleepiness Scale (KSS), a nine point Visual Analog Scale of alertness/sleepiness, was used to assess subjective sleepiness. The KSS is a scale from 1 to 9, from minimum to maximum sleepiness.