To assess next day driving ability and psychomotor/memory function following a single night time dose of eszopiclone in insomnia patients.

The study is a single centre, randomised, double blind, placebo controlled 2-way crossover design in a group of 32 male and female primary insomnia patients. The medications under investigation are eszopiclone and placebo. Patients will receive the study medications and placebo on the evening of Day 2 of each treatment period. Performance will be assessed on Day 3 of each treatment period. Each treatment period will be separated by at least a 7-day washout period. This study was previously posted by Sepracor Inc. In October 2009, Sepracor Inc. was acquired by Dainippon Sumitomo Pharma., and in October 2010, Sepracor Inc's name was changed to Sunovion Pharmaceuticals Inc.

Inclusion Criteria:

• Aged between 18 and 55 years inclusive
• In good health as determined by a medical history, ECG, haematology, blood and urine biochemistry and physical examination by the doctor
• Diagnostic and statistical manual of mental disorders, defined primary insomnia
• A body mass index greater than or equal to 18 and less than or equal to 30
• Registered with a general practitioner (GP)
• Hold a full current driving licence for at least one year, and be regular car drivers

Exclusion Criteria

• The use of any other medication during the study with the exception of oral, transdermal, IUDs (progestogen only contraceptive e.g. Mirena), or depot contraceptives, non-steroidal analgesics (e.g. ibuprofen), and paracetamol. A 7-day washout period is required for any patient currently receiving prescription or non-prescription sleep medication.
• Diagnosed sleep disorder or confirmed symptoms other than primary insomnia (e.g. restless leg syndrome, sleep apnoea)
• Significant history of mental illness, significant drug allergy, malignancy or chronic drug abuse (including alcohol)
• Any subject with known hypersensitivity to any of the study treatments
• A sleep/wake cycle other than primary insomnia (e.g. shift work) liable to prejudice the results of the study
• Pregnant or lactating females, and females of child bearing potential not using effective contraception
• Patients who habitually smoke more than 5 cigarettes per day
• Caffeine consumption of more than 5 cups or glasses per day
• History of alcohol or drug dependence or intake of more than the equivalent of 14 units of alcohol per week for females and 21 units per week for males
• Current participation in another clinical trial, or participation in a clinical trial within the last 90 days