Randomized, Double-Blind, Placebo-Controlled, Parallel-Group, Multi-Center Trial Comparing the Effects of Orally Administered Xyrem(R) (Sodium Oxybate) With Placebo for the Treatment of Fibromyalgia

Study start date: July 1, 2004

Inclusion Criteria * Sign \& date informed consent * Willing \& able to complete trial as described in protocol * \> 18 years of age * Meet American College of Rheumatology criteria for Fibromyalgia \[Widespread pain for at least 3 months, including all of the following: (1) Pain on right \& left sides of body; (2) Pain above \& below waist; (3) Pain in axial skeleton; 4) Pain on digital palpation with approximately 4kg force in at least 11 of 18 tender point sites\] * (Study continuation) Have an average VAS pain score \> 4 on a scale of 0 to 10 as recorded in patient diary the last week before Visit 4. * Discontinue all prescription medication taken for fibromyalgia, including opiates, benzodiazepines, anticonvulsants taken for pain, antidepressants, cyclobenzaprine (Flexeril), and/or tramadol (Ultram) until study completion * Continue all pre-existing nutritional and/or exercise regimens and/or behavioral, massage, acupuncture, physical or cognitive therapies on an unchanged, consistent \& regular schedule throughout study * Use only acetaminophen or over-the-counter non-steroidal anti-inflammatory drugs as rescue pain medications \& to limit dose to the labeled over-the-counter maximum. Aspirin may only be used as a cardiac protectant; formulations with caffeine are excluded. * Forego ingestion of alcohol for duration of study. * Fertile females must use a medically accepted method of birth control (e.g., barrier method with spermicide, oral contraceptive, or abstinence) for duration of trial. Exclusion Criteria 1. Have any of the following medical conditions: * Other rheumatic disease, such as rheumatoid arthritis, osteoarthritis, or systemic lupus erythematosis * Uncontrolled hypo- or hyper-thyroidism of any type * Unstable cardiovascular, endocrine, neoplastic (excluding localized basal cell carcinoma), gastrointestinal, hematologic, hepatic, immunologic, metabolic, neurological, pulmonary, and/or renal disease which would place patient at risk during trial or compromise objectives outlined in protocol * Myocardial infarction within last six months * On their screening PSG (polysomnogram) have an Apnea Index greater than 10 per hour or an Apnea Hypopnea Index greater than 15 per hour. Note: patients with sleep apnea are not excluded if their indices are below these thresholds while sleeping with CPAP (Continuous Positive Airway Pressure) and they are compliant with CPAP therapy. * Problems that, in the investigator's opinion, would preclude the patient's participation and completion of this trial or compromise reliable representation of subjective symptoms. * If a patient will have to discontinue antidepressant medication taken for depression, the investigator must make an evaluation as to any risks from cessation of anti-depressant therapy. If, in the opinion of the investigator, a reasonable risk of resultant patient harm exists, patient is excluded from study participation * Current or recent history of substance abuse including alcohol abuse * History of seizure disorder, history of head trauma, migraine headaches or intracranial surgery, \& are taking anticonvulsants * Succinic semialdehyde dehydrogenase deficiency 2. Have taken any of these therapies: * gamma-hydroxybutyrate (sodium oxybate) in 30 days prior to signing informed consent * any investigational therapy in 30 days prior to signing informed consent * ever taken anticonvulsants to treat epilepsy or any other convulsions 3. Unwilling to stop these therapies during course of trial: * anticonvulsants prescribed solely for pain * all antidepressants * medication for sleep 4. Have any of the following clinical laboratory results: * Serum creatinine \> 2.0 mg/dL * TSH (Thyroid Stimulating Hormone) \< 0.3 μU/mL OR TSH \> 6 μU/mL * abnormal liver function tests (SGOT \[AST\] or SGPT \[ALT\] more than twice the upper limit of normal) * elevated serum bilirubin (more than 1.5 times the upper limit of normal) * pre-trial ECG with arrhythmia, greater than a first degree AV block * positive pregnancy test at any time during trial 5. Have any of the following socio-economic factors: * Pending worker's compensation litigation or related other monetary settlements * Have an occupation that requires variable shift work or routine night shifts