Daily pain diary consists of 11-point NRS ranging from 0(no pain) to 10(worst possible pain). Participants rated their pain during past 24 hours, self-assessment done daily at awakening. Baseline=Last 7 available pain scores before taking study medication up to and including Day 1. Final weekly (endpoint) mean pain score is defined as the mean pain score from the last 7 pain diary entries in the study while the participant was on study medication.

Full Analysis Set (FAS) included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. Missing data were imputed using last observation carried forward (LOCF) method. 'N' (number of participants analyzed) signifies participants evaluable for this measure.

Number of participants with categorical change in overall status. PGIC: a participant-rated instrument assessing change in participant's overall status from baseline, on a scale ranging from 1 (very much improved) to 7 (very much worse).

FAS included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. Missing data were imputed using LOCF method. 'N' (number of participants analyzed) signifies participants evaluable for this measure.

Daily quality of sleep diary consists of 11-point NRS ranging from 0(best possible sleep) to 10(worst possible sleep). Participants rated their quality of sleep during past 24 hours, self-assessment done daily upon awakening. Baseline=Last 7 available scores before taking study medication up to and including Day 1. The endpoint (up to week 14) mean quality of sleep score was based on Least Squares (LS) Means using ANCOVA, with treatment group and center in the model and the baseline mean sleep score used as the covariate. Final weekly (endpoint) mean sleep quality score is defined as the mean sleep quality score from the last 7 sleep diary entries in the study while the participant was on study medication.

FAS included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. Missing data were imputed using LOCF method. 'N' (number of participants analyzed) signifies participants evaluable for this measure.

Daily quality of sleep diary consists of 11-point NRS ranging from 0(best possible sleep) to 10(worst possible sleep). Participants rated their quality of sleep during past 24 hours, self-assessment done daily upon awakening. Baseline=Last 7 available scores before taking study medication up to and including Day 1. The weekly mean quality of sleep score was based on LS Means using mixed model repeated measures ANCOVA, with treatment, center, week, and treatment-by-week interaction in the model and the baseline mean sleep score used as the covariate. Weekly mean sleep quality score is defined as the mean of the last 7 daily sleep diary entries.

FAS included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. 'N' (number of participants analyzed) signifies participants evaluable for this measure. 'n' participants evaluable at given time point for each group, respectively.

Participant-rated 12 item questionnaire assess constructs of sleep over past week.7 subscales: sleep disturbance, snoring, awakened short of breath, sleep adequacy, somnolence (range:0-100); sleep quantity(range:0-24), optimal sleep(yes or no), as well as a 9-item overall sleep problems index. Except Adequacy, Optimal, Quantity of sleep, higher scores=more impairment. Scores transformed(actual raw score minus lowest possible score divided by possible raw score range*100);total score range:0-100,higher score=more disturbance.

FAS included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. Missing data were handled using LOCF method. 'N' (number of participants analyzed) signifies participants evaluable for this measure.

Participant-rated 12 item questionnaire assess constructs of sleep over past week.7 subscales: sleep disturbance, snoring, awakened short of breath, sleep adequacy, somnolence (range:0-100); sleep quantity(range:0-24), optimal sleep(yes or no), as well as a 9-item overall sleep problems index. Except Adequacy, Optimal, Quantity of sleep, higher scores=more impairment. Scores transformed(actual raw score minus lowest possible score divided by possible raw score range*100);total score range:0-100,higher score=more intensity of attribute.

FAS included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. Missing data were handled using LOCF method. 'N' (number of participants analyzed)=participants evaluable for this measure. 'n'=participants evaluable for specified category for each arm group.

FIQ: 20-item self-administered questionnaire designed to assess areas such as health status, progress, and outcomes in participants with fibromyalgia. 11 items related to physical functioning, other items assess pain, fatigue, stiffness, difficulty working, and symptoms of anxiousness and depression. FIQ contains 10 sub-scales scored from 0 to 10, with higher scores indicating more impairment in the subscale attribute. Total score range from 0 to 100 with higher scores indicating more impairment.

FAS included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. Missing data were imputed using LOCF method. 'N' (number of participants analyzed) signifies participants evaluable for this measure. 'n'=participants evaluable for specified category for each arm group, respectively.

FIQ: 20-item self-administered questionnaire designed to assess areas such as health status, progress, and outcomes in participants with fibromyalgia. 11 items related to physical functioning, other items assess pain, fatigue, stiffness, difficulty working, and symptoms of anxiousness and depression. FIQ contains 10 sub-scales scored from 0 to 10, with higher scores indicating more impairment in the subscale attribute. Total score range from 0 to 100 with higher scores indicating more impairment.

FAS included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. Missing data were imputed using LOCF method. 'N' (number of participants analyzed) signifies participants evaluable for this measure.

SF-36 is a standardized survey evaluating 8 aspects of functional health and well being: physical functioning, role physical, bodily pain, general health, vitality, social functioning, role emotional and mental health. The score for a section is an average of the individual question scores, which are scaled 0-100 (100=highest level of functioning) and is reported as 2 summary scores; Physical Component Score and Mental Component Score. Total score range for the summary scores = 0- 100, where higher score represents higher level of functioning.

FAS included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. Missing data were imputed using LOCF method. 'N' (number of participants analyzed) signifies participants evaluable for this measure.

MAF is a 16-item self-administered questionnaire that yields a Global Fatigue Index (GFI), measures 4 dimensions of fatigue: degree and severity, amount of distress it causes, its timing and degree to which fatigue interferes with activities of daily living. Only 15 items are used to calculate the GFI. GFI score range from 1 (no fatigue) to 50 (severe fatigue).

FAS included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. Missing data were imputed using LOCF method. 'N' (number of participants analyzed) signifies participants evaluable for this measure.

HADS: participant rated questionnaire with 2 subscales. HADS-A assesses state of generalized anxiety (anxious mood, restlessness, anxious thoughts, panic attacks); HADS-D assesses state of lost interest and diminished pleasure response (lowering of hedonic tone). Each subscale comprised of 7 items with range 0 (no presence of anxiety or depression) to 3 (severe feeling of anxiety or depression). Total score 0 to 21 for each subscale; higher score indicates greater severity of anxiety and depression symptoms.

FAS included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. Missing data were imputed using LOCF method. 'N' (number of participants analyzed) signifies participants evaluable for this measure.

Pain visual analog scale (VAS): Participants assessed the severity of their pain using a 100 mm visual analog scale (VAS). The scale ranged from 0 (no pain) to 100 (worst possible pain), measurement on a scale corresponds to the magnitude of their pain.

FAS included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. Missing data were imputed using LOCF method. 'N' (number of participants analyzed) signifies participants evaluable for this measure.

Acetaminophen (up to 4 gram/day as needed for pain relief) was an allowable concomitant medication as a rescue therapy. The total daily acetaminophen dose taken during double-blind treatment was calculated for each participant as: (total acetaminophen dose during the study) divided by (total number of study days).

FAS included all randomized participants who received at least 1 dose of study medication, regardless of medication compliance. Missing data were imputed using LOCF method. 'N' (number of participants analyzed) signifies participants evaluable for this measure.