A 1-year safety and efficacy study of duloxetine in patients with fibromyalgia.

Author(s): Chappell AS, Littlejohn G, Kajdasz DK, Scheinberg M, D'Souza DN, Moldofsky H

Affiliation(s): Lilly Research Laboratories, Eli Lilly and Co, Indianapolis, IN 46285, USA. aschappell@lilly.com

Publication date & source: 2009-06, Clin J Pain., 25(5):365-75.

Publication type: Multicenter Study; Randomized Controlled Trial; Research Support, Non-U.S. Gov't

OBJECTIVES: Evaluate the efficacy and safety of duloxetine at doses up to 120 mg once daily in patients with fibromyalgia. METHODS: This was a phase 3, 60-week study, which included an 8-week open-label period followed by a 52-week, randomized, double-blind period. Patients received duloxetine 30 mg daily for 1 week and duloxetine 60 mg daily for 7 weeks and were then randomized to receive either 60 or 120 mg daily (1:2 ratio). RESULTS: Enrolled patients (N=350, 95.7% female) exhibited moderate disease symptoms at study entry (Brief Pain Inventory average pain=6.7, Clinical Global Impression of Severity=4.1, and Patient's Global Impression of Severity=4.1). Significant pain reduction in patients was observed during the open-label study phase. This pain reduction continued during the 52-week double-blind study phase, as demonstrated by additional mean decreases in the Brief Pain Inventory average pain score within both duloxetine groups. The most common (> or =15%) treatment-emergent adverse events (overall phase) were nausea, headache, insomnia, dizziness, constipation, and dry mouth. Seventy-four (21.1%) patients reported adverse events as a reason for discontinuation [most common (>1%) were insomnia, vomiting, diarrhea, dizziness, and nausea]. The mean change (SD) in sitting systolic blood pressure (mm Hg) was -0.1 (14.4), in sitting diastolic blood pressure was -0.2 (9.6), in sitting pulse rate was 1.9 (10.4) bpm, and in weight was 0.7 (4.3) kg. DISCUSSION: The profile of duloxetine for the long-term treatment of fibromyalgia was consistent with that seen in other indications for which the drug is currently marketed.