A Study of Duloxetine in Adolescents With Juvenile Primary Fibromyalgia Syndrome

Inclusion Criteria

• Meet criteria for primary JPFS
• Have a score of greater than or equal to 4 on Brief Pain Inventory (BPI) average pain severity (Item 3) during screening
• Female participants must have a negative serum pregnancy test during screening
• Participant's parent/legal representative and participant judged to be reliable to keep all appointments for clinical tests and procedures
• Participant's parent/legal representative and participant must have a degree of understanding such that they can communicate intelligently
• Participants must be capable of swallowing investigational product whole
• Participants must have venous access sufficient to allow blood sampling and be compliant with blood draws

Exclusion Criteria

• Currently enrolled in, or discontinued within the last 30 days from, a clinical trial involving an investigational drug or device or off-label use of a drug or device or concurrently enrolled in any other type of medical research
• Previously completed or withdrawn after randomization from a study investigating duloxetine
• Known hypersensitivity to duloxetine or any of the inactive ingredients, or have frequent or severe allergic reactions to multiple medications
• Treated with duloxetine within the last 6 months. Will not likely benefit from duloxetine treatment, in the opinion of the investigator or have had prior nonresponse or inadequate tolerance to duloxetine
• Pain symptoms related to traumatic injury, past surgery, structural bone or joint disease or regional pain syndrome that will interfere with interpretation of outcome measures
• Currently have evidence of rheumatologic disorder or have a current diagnosis of rheumatoid arthritis, inflammatory arthritis, or infectious arthritis, or an autoimmune disease (for example, systemic lupus erythematosus)
• Have a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) Axis I condition, currently or within the past year, except major depressive disorder (MDD) and/or generalized anxiety disorder (GAD), adjustment disorder or specific phobias with primary investigator approval
• Have a current secondary DSM-IV Axis I condition of attention-deficit/hyperactivity disorder that requires pharmacologic treatment
• Lifetime DSM-IV Axis I diagnosis of psychosis, bipolar disorder, or schizoaffective disorder
• DSM-IV Axis II disorder which would interfere with protocol compliance
• History of substance abuse or dependence within the 6 months
• Positive urine drug screen for any substances of abuse or excluded medication
• Family history of 1 or more first-degree relatives with diagnosed bipolar I disorder
• Significant suicide attempt within 1 year of screening or are currently at suicidal risk in the opinion of the investigator
• Weight less than 20 kilogram (kg) at screening
• History of seizure disorder (other than febrile seizures)
• Taking any excluded medications that cannot be discontinued at screening
• Fluoxetine within 30 days prior to completion of screening
• Monoamine oxidase inhibitor (MAOI) within 14 days of screening; or the potential need to use an MAOI during the study or within 5 days of discontinuation of investigational product
• Abnormal thyroid-stimulating hormone (TSH) concentrations
• Uncontrolled narrow-angle glaucoma
• Acute liver injury (such as hepatitis) or severe cirrhosis (Child-Pugh Class C)
• Serious or unstable medical illness
• Female participants who are either pregnant, nursing or have recently given birth