Nearly six times more common in women than in men, fibromyalgia is a chronic, incapacitating musculoskeletal disorder marked by widespread body pain and muscle tenderness. Fibromyalgia has been linked to abnormalities in the brain's neurotransmitters, serotonin and norepinephrine - chemicals widely recognized for their role in depression. In a clinical trial conducted for the treatment of fibromyalgia, the antidepressant duloxetine was shown to significantly reduce pain and improve a range of disease symptoms. The results appear in Arthritis & Rheumatism.
"Our results suggest that duloxetine improves pain and tenderness, the hallmark characteristics of fibromyalgia," said Lesley M. Arnold, who coordinated the research. "The effect of duloxetine on the reduction of pain appears to be independent of its effect on mood."
The majority of the participants in the study were women. Just over a third of the patients - 38 percent - had been diagnosed with depression. On a random basis, the patients were prescribed one of two treatments for a course of 12 weeks. About half, 104 individuals, received 60 milligrams of duloxetine twice a day. The remaining 103 patients were given a placebo. Both groups were evaluated and scored, using the Fibromyalgia Impact Questionnaire. In various measures of disease - from pervasive pain to tiredness to tenderness - the female fibromyalgia patients treated with duloxetine improved significantly over those treated with a placebo. One of the most dramatic changes was in the reduction of the number of tender points - places on the body where it hurts to touch - and the increase of pressure pain threshold. Women with or without depression receiving duloxetine benefited emotionally and physically, reporting improvements in general mood, ability to function, and overall enjoyment of life.
Dr. Arnold notes that further research is needed on larger samples and other groups with fibromyalgia to evaluate duloxetine's effectiveness.
