Source: DGNews  |  Posted 2 years ago

By Jennifer Reising

SAN ANTONIO, Tex -- February 9, 2010 -- In patients with fibromyalgia and comorbid major depressive disorder (MDD), duloxetine hydrochloride directly and indirectly reduces pain, in addition to improving mood. The findings were presented here at the 26th annual meeting of the American Academy of Pain Medicine (AAPM).

Response in pain or mood was similar in patients with fibromyalgia and MDD, regardless of the severity of MDD or pain at baseline. Improvement in pain and improvement in MDD are positively correlated.

“These data support the independent analgaesic properties of duloxetine in the treatment of fibromyalgia,” said Laurence Bradley, PhD, University of Alabama at Birmingham, Birmingham, Alabama, on February 3.

For the study, Dr. Bradley and colleagues pooled data from 4 double-blind, placebo-controlled, randomised trials evaluating duloxetine 60 to 120 mg in 1,332 patients with fibromyalgia. This study evaluated the 350 patients (26%) who also had MDD (147 placebo, 203 duloxetine).

Pain response was defined as >=30% reduction in average pain as measured by the Brief Pain Inventory (BPI), and a mood response was defined as a 50% improvement from baseline in the Hamilton Depression rating scale (HAM-D17) or Beck Depression Inventory (BDI) total scores.

The researchers found no differences in pain response across baseline MDD severities (treatment-by-severity interaction P > .1) or in MDD response across baseline pain severities (interaction P > .1).

Path analysis indicated that 69% of the improvement in pain was a direct effect (P = .09), with improvement in mood accounting for 31%. For mood improvement, 60% was direct effect (P = .2), and 40% was due to pain improvement.

“Improvement in pain reflected greater direct treatment effect with an indirect effect of improved mood, indicating that the improvement seen with duloxetine in fibromyalgia is not solely a mood effect,” the authors wrote. “Similarly, improvement in mood was found to reflect greater direct effect on mood, with pain improvements also contributing to mood improvement.”

Funding for this study was provided by Eli Lilly and Company and Boehringer Ingelheim.

[Presentation title: Fibromyalgia and Comorbid Major Depressive Disorder: Assessment of Mood and Pain Response to Duloxetine Hydrochloride Compared to Placebo. Abstract 121]