A European Multicenter Randomized Double-blind Placebo-controlled Monotherapy Clinical Trial of Milnacipran in Treatment of Fibromyalgia

Objective. This randomized, double-blind, placebo-controlled, multicenter study investigated the efficacy and safety of milnacipran in the treatment of fibromyalgia (FM) in a European population. Methods. Outpatients diagnosed with FM according to 1990 American College of Rheumatology criteria (N = 884) were randomized to placebo (n = 449) or milnacipran 200 mg/day (n = 435) for 17 weeks (4-week dose escalation, 12-week stable dose, 9-day down-titration), followed by a 2-week posttreatment period. The primary efficacy criterion was a 2-measure composite responder analysis requiring patients to achieve simultaneous improvements in pain (>= 30% improvement from baseline in visual analog scale, 24-hour morning recall) and a rating of "very much" or "much" improved on the Patient Global Impression of Change scale. If responder analysis was positive, Fibromyalgia Impact Questionnaire (FIQ) was included as an additional key primary efficacy measure. Results. At the end of the stable dose period (Week 16), milnacipran 200 mg/day showed significant improvements from baseline relative to placebo in the 2-measure composite responder criteria (p = 0.0003) and FIQ total score (p = 0.015). Significant improvements were also observed in multiple secondary efficacy endpoints, including Short-Form 36 Health Survey (SF-36) Physical Component Summary (p = 0.025), SF-36 Mental Component Summary (p = 0.007), Multidimensional Fatigue Inventory (p = 0.006), and Multiple Ability Self-Report Questionnaire (p = 0.041). Milnacipran was safe and well tolerated; nausea, hyperhidrosis, and headache were the most common adverse events. Conclusion. Milnacipran is an effective and safe treatment for pain and other predominant symptoms of FM. Registered as trial no. NCT00436033. (First Release Feb 15 2010; J Rheumatol 2010;37:851-9; doi: 10.3899/jrheum.090884)