A Study to Compare Efficacy and Safety of Zolpidem Modified Release Formulation Versus Zolpidem in Insomnia Patients

A Randomized, Active Control, Parallel Study to Evaluate the Efficacy and Safety of Zolpidem MR (Stilnox CR) Versus Zolpidem (Stilnox) in Patients With Primary Insomnia

The purpose of this study is to investigate the efficacy and safety of zolpidem MR (modified release) compared to zolpidem IR (immediate release) in patients with primary insomnia.

Inclusion Criteria:

• Diagnosis of primary insomnia based on DSM-IV criteria (307.42)
• Written informed consent has been obtained

Exclusion Criteria:

• Patients with sleep apnea syndrome, narcolepsy, presence or suspicion of periodic leg movement or restless leg syndrome
• Patients with hepatic failure, myasthenia gravis, or hypersensitivity to zolpidem
• Patients who are known to be current drug or alcohol abuser or likely to concomitantly consume alcoholic beverages (more than 3 times/week)
• Patients who have received antihistamines or antipsychotics will not allow to discontinue the previous medication throughout the study
• Patients who are pregnant, lactating or intend to become pregnant during the study period
• Patients who have received antidepressants or anxiolytics will not allow to change the dose or discontinue the previous medication throughout the study
• Any clinically significant condition, which in the opinion of the investigator makes the patients unsuitable for the trial
• Participation in any clinical trial within 1 month prior to randomization