SAN DIEGO — Antidepressants do not interfere with the efficacy or safety of pregabalin in patients with fibromyalgia, and can therefore be safely continued, a new study has found.
Up to 70% of patients with fibromyalgia suffer comorbid depression. This study should provide some reassurance to clinicians who have wondered whether to continue antidepressant therapy in patients being treated with pregabalin.
"Clinical trials of pregabalin excluded patients on antidepressants. This is the first study to show that pregabalin can help patients with fibromyalgia who are concurrently on antidepressants," said lead investigator Lesley Arnold, MD, from the University of Cincinnati College of Medicine.
Results from the double-blind, placebo controlled, crossover study were presented during the late-breaking session here at the American College of Rheumatology (ACR) 2013 Annual Meeting.
Most of the 197 participants were white and female, and the mean age was 50 years. All met ACR criteria for fibromyalgia, had a documented history of depression, and were stabilized with antidepressant therapy — either a selective serotonin reuptake inhibitor or a serotonin norepinephrine reuptake inhibitor.
Participants were randomly assigned to 6 weeks of treatment with twice-daily pregabalin, starting at 150 mg/day and optimized on the basis of response to 300 to 450 mg/day, or placebo. After a 2-week washout period, participants were switched to the other group for 6 weeks.
At baseline, the mean pain score on a 10-point numeric rating scale was 6.70, indicating moderate to severe pain. "The pain level at baseline is similar to that seen in other fibromyalgia trials," Dr. Arnold reported.
After the first week of therapy, patients in the pregabalin group achieved a significant reduction in pain severity; this was maintained throughout both 6-week periods.
At the end of the study, the mean pain score dropped from 6.70 to 5.45 in the placebo group and to 4.84 in the pregabalin group in a last observation carried forward analysis (P = .0001).
For both 6-week periods combined, there was a 28% reduction in pain severity with pregabalin, which Dr. Arnold called statistically and clinically meaningful.
The safety profile of pregabalin is consistent with current labeling and other trials, and no new safety signals emerged. Adverse events were more frequent with pregabalin than with placebo (77.3% vs 59.9%). The most common adverse events associated with pregabalin were dizziness (28.2%) and drowsiness (19.9%). Four serious adverse events were reported — 3 in the pregabalin group and 1 in the placebo group. The rate of discontinuation related to adverse effects was higher with pregabalin than with placebo (6.1% vs 3.4%).
"This study shows that pregabalin has a role in patients with fibromyalgia and depression stabilized on antidepressant medications," Dr. Arnold said.
The effect of pregabalin on depression has not yet been analyzed, she noted.
Fibromyalgia is difficult to treat, said Roberto Caricchio, MD, from Temple University in Philadelphia. "You can treat fibromyalgia, patients get better, and then it can recur. This study of patients with both depression and fibromyalgia suggests that we now have more tools for patients with coexisting depression and fibromyalgia. It is an encouraging study."
This study was sponsored by Pfizer. Dr. Arnold reports financial relationships with Pfizer, Eli Lilly, Takeda, AstraZeneca, Forest Labs, Theravance, Dainippon Sumitomo Pharma, Daiichi Sankyo, and Purdue Pharma. Dr. Caricchio reports receiving funding from the National Institutes of Health.
ACR 2013 Annual Meeting: Abstract L6. Presented October 30, 2013.
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Cite this: Pregabalin Works in Fibromyalgia Patients on Antidepressants - Medscape - Nov 05, 2013.