"There are no approved drugs for fibromyalgia," said presenting author Michael J. Detke, MD, PhD, medical director for Cymbalta at Lilly Research Laboratories, Indianapolis, Indiana. "It's a significant medical problem."

Although the same serotonin and norepinephrine systems responsible for depression are dysfunctional in patients with fibromyalgia, Dr. Detke said duloxetine's pain-relieving effect appears independent from its effect on mood.

The researchers presented two randomized, placebo-controlled, double-blind studies of women with fibromyalgia according to the American College of Rheumatology criteria and significant pain (an intensity of at least 4 on the Fibromyalgia Impact Questionnaire or Brief Pain Inventory). Twenty-five to 40% of the patients had a current major depressive disorder and all baseline characteristics were similar between treatment arms.

In the first study, 92 women received 60 mg of duloxetine twice daily while another 92 received placebo. In the second study, 118 were randomized to 60 mg of duloxetine once daily, 116 to a dose of 60 mg twice daily, and another 120 to placebo.

Average pain scores were significantly lower by about 1 point in both studies for the duloxetine groups compared with placebo, but there was no difference between once and twice daily dosing groups in the second study. Both studies showed significantly greater percentages of patients achieving a 50% reduction in pain on duloxetine versus placebo, which Dr. Detke called a "pretty robust" finding.

Fatigue and rest scores showed similar significant reductions in the second study for duloxetine versus placebo. The reductions were not significant in the first study.

Patients with and without major depressive disorder experienced the same significant reduction in pain compared to placebo. No significant interaction between pain alleviation and depression was found in either study.

The authors concluded that duloxetine was safe and effective in treating fibromyalgia pain.


[Presentation title: Duloxetine in the Treatment of Fibromyalgia in Women -- Results from Two Clinical Trials. Poster 144]

Copyright © 2009 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content.