A Study of Duloxetine in Fibromyalgia

The purpose of the study is to assess the effectiveness and safety of duloxetine in participants with fibromyalgia.


Eligibility Criteria:
Inclusion Criteria:

* Participants fulfilling the following criteria in the American College of Rheumatology 1990 Criteria for the Classification of Fibromyalgia
* Participants with pain rated severity 4 or over by Brief Pain Inventory (BPI) - average pain severity item (Question 3)

Exclusion Criteria:

* Participants with serious cardiovascular, hepatic, renal, respiratory, or hematological disease, or clinically significant laboratory or electrocardiogram abnormality which indicate a serious medical problem or require significant intervention in the judgment of the investigators
* Participants with alanine aminotransferase/aspartate aminotransferase of not less than 100 international units per liter (IU/L) or total bilirubin of not less than 1.6 milligrams per deciliter (mg/dL)
* Participants with serum creatinine level of not less than 2.0 mg/dL, participant who has undergone kidney transplantation or hemodialysis
* Participants with pain difficult to discriminate from pain associated with fibromyalgia or disease which disturbs the assessment
* Participants with treatment-refractory fibromyalgia
* Participants with thyroidal dysfunction, excluding those assessed by the investigator that the disorder is controlled as appropriate by 3-month or longer drug therapy
* Participants with present or past history of rheumatoid arthritis, inflammatory arthritis, infectious arthritis, or auto immune disease rather than thyroid deficiency
* Participants with an axis I condition according to Diagnostic and Statistical Manual of Mental Disorders Fourth Edition (DSM-IV), currently or within the past year, except for major depressive disorders
* Participants with a lifetime diagnosis of bipolar disorder or schizoaffective disorder; or any other disorder with psychotic symptoms - based on the clinical opinion of the investigator
* Participants with personality disorder or mental retardation
* Participants with uncontrolled angle closure glaucoma
* Participants with present or past history of uncontrolled seizures or convulsion disorders
* Participants with suicidal ideation within past 6 months, with suicidal attempt within past 1 year
* Participants answering "yes" to any of the questions about active suicidal ideation/intent/behaviors occurring within the past 6 months (Columbia Suicide Severity Rating Scale, Suicide Ideation section - Questions 4 and 5; Suicidal Behavior section)
* Participants with past history of multiple episodes of drug allergy
* Female participants who are pregnant, lactating, or who want to get pregnant during the study period. Male participants who want his partner to get pregnant
* Females of child-bearing potential who can't agree to utilize medically. acceptable and reliable means of birth control during the study and for 1 month following the last dose of the study
* Participants with a history of alcohol or any psychoactive substance abuse or dependence (including alcohol, but excluding nicotine and caffeine) within the past 1 year
* Participants who have a positive urine drug screen for any substance of abuse (phencyclidine, cocaine, antihypnotic agent, or cannabis)
* Participants previously treated with duloxetine