Desvenlafaxine: Is effective for Fibromyalgia?
Fibromyalgia is a musculoskeletal disease that affects women more than men. Patients diagnosed with fibromyalgia may experience fatigue, muscle tenderness, depression, although not every patient has the same symptoms. Fibromyalgia is difficult to diagnose due to its wide-ranging symptoms.
Antidepressants are very helpful in relieving fibromyalgia pain and improve deep restorative sleep. They work by balancing serotonin and other brain chemicals involved in pain processing. Desvenlafaxine is serotonin–norepinephrine reuptake inhibitors (SNRIs) antidepressant medication used in the treatment of major depression and other mood disorders. They are sometimes also used to treat anxiety disorders, fibromyalgia syndrome (FMS).
Trials of desvenlafaxine for fibromyalgia syndrome (FMS) in two multicenter, randomized, placebo-controlled, adaptive-design were conducted. The patients (both males & females) were randomized to 27-week treatment with placebo or desvenlafaxine 50, 100, 200, or 400 mg/d in study 1 and in study 2, female patients were randomized to 8 week treatment with placebo, desvenlafaxine 200 mg/d, or pregabalin 450 mg/d after a placebo run-in. The primary endpoint of the study was changed from baseline in numeric rating scale pain score.
In study 1, about 697 patients were randomly assigned to treatment. Interim analysis was conducted (n = 346), found that desvenlafaxine doses met the efficacy criteria and the study was terminated. And before the planned interim analysis, study 2 was ceased owing to business reasons. At week 8, numeric rating scale pain scores were –1.98 (0.37), –1.60 (0.37), and –1.70 (0.38) for placebo (n = 26), desvenlafaxine 250 mg/d (n = 24), and pregabalin 450 mg/d (n = 21), respectively; neither active treatment differed significantly from placebo.
However, desvenlafaxine treatment was generally safe and well tolerated, but efficacy of desvenlafaxine for pain related to FMS was not demonstrated.