Milnacipran: A New Treatment for Fibromyalgia Syndrome

Abstract

Objective: To review the pharmacology, efficacy, and tolerability of milnacipran, a dual serotonin-norepinephrine reuptake inhibitor (SNRI), in the treatment of symptoms of fibromyalgia syndrome and associated fibromyalgia pain. Data Sources: English-language articles were obtained via searches of MEDLINE (1950-January 2010), EMBASE (1980-January 2010), and International Pharmaceutical Abstracts (1970-January 2010), using the key words milnacipran, fibromyalgia, serotonin-norepinephrine reuptake inhibitors, F 2207, and pain management. Bibliographies of selected articles were used to identify additional sources. Study Selection and Data Extraction: Available published articles reporting the results of human studies of milnacipran were reviewed for inclusion in this article. Additional information regarding pharmacology, adverse events, contraindications, and precautions was obtained from the manufacturer's prescribing information. Data Synthesis: Milnacipran is a dual SNRI approved for the treatment of fibromyalgia symptoms and pain. Milnacipran is well absorbed upon oral administration, has limited first-pass elimination, has a short halflife, and is not metabolized by the cytochrome P450 enzyme group. Phase 3 clinical trials evaluating the efficacy of milnacipran demonstrated a 10–20% higher composite response rate compared with placebo in the treatment of fibromyalgia symptoms and associated pain when milnacipran was given in doses of 100–200 mg/day. Significant improvements in physical functioning, fatigue, cognition, and mental health were also noted. Milnacipran appears to have fewer anticholinergic, sedative, and cardiovascular adverse effects compared with other pharmacologic treatments of fibromyalgia. Nausea was the most commonly reported adverse event. Conclusions: Milnacipran is an effective treatment for the symptoms of fibromyalgia syndrome and associated pain. Additional studies are needed to assess comparative effectiveness with that of other pharmacologic treatments of fibromyalgia syndrome, long-term efficacy, and safety.