insomnia and daytime function in osteoarthritis

Conditions: Sleep Disorders

Summary: to assess the efficacy and safety of zolpidem at doses up to 10 mg compared to placebo in patients with insomnia associated with osteoarthritis


Eligibility criteria:
inclusion criteria: * patients that are male or female aged 45 years or older. * patients having given their written informed consent prior to participating in the trial. * patients who have had oa of the knee or hip for at least 6 months, as diagnosed using the american college of rheumatology classification criteria for osteoarthritis. * patients who, based on historical data, developed insomnia together with or after development of arthritic symptoms and presently have difficulty in maintaining sleep or have non-restorative sleep for at least three months preceding study entry and have difficulties with daytime activities because of problems with sleeping. * patients who, based on historical data, experience sleep disturbance at least 3 nights per week. * patients must have a score of greater than 1 on the likert pain scale within two weeks of study participation while taking pain medication * patients must have been on a stable dosing regimen of analgesic/anti-inflammatory medication for one month prior to study entry and agree to maintain the dose throughout the study. patient must agree not to exceed 4000 mg (i.e., 1000 mg acetaminophen, 4 times per day) as rescue medication in case of unexpected arthritis pain. acetaminophen is the only rescue medication allowed in addition to the patient's stable dosing regimen. exclusion criteria: * female patients that are pregnant or are breast-feeding. * patients with reproductive potential not implementing adequate contraceptive measures. * patients with mental disorders or who cannot be relied upon to understand the trial requirements and comply with the treatment regimen. * patients that are shift workers or have required a change in their regular sleep schedule by at least three hours within the last three months. * patients that have been treated for insomnia within 2 years prior to the onset of osteoarthritis. * patients that have a history of recurrent major depressive disorder over the last 3 years or any single episode of major depression over the last 2 years. * patients having a history of seizures or other significant neurological diseases. * patients with a history of myasthenia gravis. * patients that have had serious head injury within the past 10 years. * patients with insulin dependent diabetes poorly controlled in the opinion of the investigator. * patients who have had a stroke or myocardial infarction in the 6 months before the screening visit. * patients with unstable angina or severe heart failure. * patients with a history of significant impairment of any organ system that could impair the ability of the patient to participate in the study. * patients with abnormal clinical laboratory tests judged by the investigator to require clinical intervention. * patients that fail to complete at least 3 of 7 consecutive nights and days (day must follow night to be consecutive) on their evening and morning questionnaires during the screening period and have not satisfied the following: 1. scored 2 or greater on the evening questionnaire, and 2. slept a total of less than 6 hours, as determined by: a wake time after sleep onset of greater than 1 hour, and/or having time to fall asleep (sleep latency) of 45 minutes or greater. * patients that have used any drug (e.g. beta-blockers, antihistamines) and subsequently reported significant cns side effects. * patients with a history of hypersensitivity/exaggerated drug response to sedative/hypnotic drugs (allergic or paradoxical), including zolpidem. * patients with a history of sleep apnea or current signs/symptoms associated with sleep apnea * patients with a history of symptoms compatible with diagnosis of periodic leg movement or restless legs syndrome. * patients with a history of cancer within the last 5 years or that have suspected neoplastic disease (with the exception of nonmelanomatous skin cancer). * patients that are taking any drugs of abuse or psychotropic drugs (including, but not limited to antidepressants, antipsychotics, or anxiolytics) or drugs with demonstrated effects on sleep-wake function (including, but not limited to herbal supplements, diphenhydramine, and theophylline). * patients that have used over-the-counter sleep medication within seven days prior to study entry. prescription sleep medications must have been discontinued at least 7-25 days prior to study entry, depending upon the half-life of the particular compound. * patients who have taken investigational drugs within 30 days of the screening visit.