Conditions: Osteoarthritis Knee Pain
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 524
Healthy volunteers: no

Brief summary:
The study will test the hypothesis that, in patients with knee pain due to osteoarthritis (OA) who are taking nonsteroidal anti-inflammatory drugs (NSAIDs) but still have significant knee pain, duloxetine 60 to 120 milligrams (mg) daily for 10 weeks will provide additional reduction in pain.

Detailed description:
Duloxetine has been studied in pain due to osteoarthritis (OA) in 2 previous placebo controlled clinical trials. In clinical practice, when nonsteroidal anti-inflammatory drugs (NSAIDs) are ineffective in reducing pain due to OA, clinicians often add a second agent without discontinuing NSAIDs. In this study, we will investigate whether adding duloxetine to NSAIDs provides additional pain relief and functional improvement in patients with knee pain due to OA.

Arms:
arm 1: None arm 2: None

Interventions: intervention 1: Duloxetine intervention 2: Placebo
Intervention descriptions: intervention 1: 30 milligrams (mg) taken by mouth, once daily for 1 week, followed by 60 to 120 mg taken by mouth, once daily for 9 weeks. intervention 2: Taken by mouth, once daily for 10 weeks

Protocol document: