Poster 6: Duloxetine 60 to 120 mg Once Daily Versus Placebo in the Treatment of Patients With Osteoarthritis Knee Pain

Article Outline

• Disclosures
• Objective
• Design
• Setting
• Participants
• Interventions
• Main Outcome Measures
• Results
• Conclusions
• Copyright

Keywords: Osteoarthritis, Duloxetine

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Disclosures 

K. Piezer, Lilly USA, LLC, Employment; Lilly USA.

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Objective 

Reduction of pain is crucial to the management of osteoarthritis (OA) as it is a common cause of disability in OA patients. Duloxetine is efficacious in treating diabetic peripheral neuropathic pain and fibromyalgia. In this study, duloxetine (60-120 mg once daily) was evaluated in the treatment of OA knee pain.

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Design 

13-week, randomized, double-blind, placebo-controlled trial.

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Setting 

Outpatients.

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Participants 

Patients meeting American College of Rheumatology clinical and radiographic criteria for OA of the knee, with pain for ≥14 days each month for 3 months before study entry and mean 24-hour average pain score ≥4.

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Interventions 

Patients were randomized to duloxetine (N = 128) or placebo (N = 128) and stratified by nonsteroidal anti-inflammatory use. At week 7, patients (33/128) who did not respond to 60-mg dose (≤30% reduction in pain) increased their dose to 120 mg.

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Main Outcome Measures 

The primary efficacy outcome was Brief Pain Inventory (BPI) 24-hour average pain, analyzed using a mixed-effects repeated measures approach. Secondary outcomes included Patient's Global Impressions-Improvement (PGI-I), Western Ontario and McMaster Universities (WOMAC) pain and physical functioning, Clinical Global Impressions-Severity (CGI-S), BPI-Severity and -Interference, and weekly 24-hour average pain. Tolerability was also assessed.

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Results 

Compared with placebo-treated patients, duloxetine-treated patients had significantly greater reductions from baseline on the primary outcome, BPI average pain, from visit 3 through visit 5 (P < .001). Compared with placebo, duloxetine significantly reduced the WOMAC total scores (P = .044), weekly 24-hour average pain (P = .008), and CGI-S (P = .009). The PGI-I was improved significantly in duloxetine treated patients from visit 3 through visit 5 (P ≤ .05). Frequency of nausea, constipation, and hyperhidrosis were significantly higher in duloxetine group compared with placebo (P ≤ .05). Significantly more duloxetine-treated patients discontinued due to adverse events (P = .002).

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Conclusions 

Compared with placebo, duloxetine treatment effectively reduced the pain and improved function in patients with OA knee pain; it was well tolerated.