Pharmacotherapy of fibromyalgia

Published evidence on the pathophysiology, diagnosis, and treatment of fibromyalgia is reviewed, with an emphasis on recent clinical trials of various pharmacologic agents. Fibromyalgia affects an estimated 2% of the general U.S. population, and its incidence is sevenfold higher among women. The diagnostic characteristics of fibromyalgia are chronic widespread pain, thought to arise from abnormalities of ascending pain and descending inhibitory sensory pathways, and allodynia on palpation of specific tender points. Three medications available in the United States are labeled for treatment of fibromyalgia-related symptoms: the serotonin- and norepinephrine-reuptake inhibitors duloxetine and milnacipran and the α(2)-δ ligand pregabalin. Evidence from clinical trials indicates that all three drugs can have a significant impact on fibromyalgia-related pain; duloxetine and pregabalin have been demonstrated to reduce sleep disturbances and improve quality of life (the former also has been shown to improve mood), while milnacipran can offer significant benefits in reducing fatigue. A growing body of evidence suggests that the best treatment approach may involve the use of one or more agents whose mechanisms of action are aligned with patient-specific clusters of symptoms. Several other agents have been used for fibromyalgia, with mixed results, including tricyclic antidepressants, selective serotonin-reuptake inhibitors, opioids, and gabapentin. Given the limitations of the evidence from clinical trials to date, controlled trials directly comparing different agents are needed to better delineate adverse-event risks, cost considerations, and optimal management approaches. A broad range of drugs has been used to treat fibromyalgia. Symptoms, comorbidities, adverse effects, and patient preference are important considerations in drug selection.