About 50% to 70% of fibromyalgia patients have a lifetime history of depression, many of whom take antidepressants to treat their depression. A common clinical question has been how to manage fibromyalgia pain in patients with comorbid depression who are stable on antidepressants. At the 2013 annual meeting of the American College of Rheumatology (ACR), my colleagues and I presented a study that addressed whether pregabalin—an FDA-approved agent for treating fibromyalgia—can help manage pain in patients concurrently taking antidepressants for depression.
Our study included 197 adults who met the ACR 1990 criteria for fibromyalgia. Participants had a documented diagnosis of depression, were on a stable dose of an antidepressant, and remained on these drugs throughout the 14-week study. Patients were then started on 150 mg/day of pregabalin, dosed twice daily; this was then optimized to 300 to 450 mg/day, dosed twice daily. The trial used a crossover, double-blind, placebo-controlled design. There were two 6-week periods; patients received pregabalin or placebo, with a 2-week break in between these periods.
The average pain severity for patients at the onset of the study was 6.7 out of 10.0 (moderate to severe). Patients on pregabalin had a significant reduction in pain severity when compared with those on placebo. Pain improvement was noted by the first week of treatment and was maintained throughout the study. On average, patients on pregabalin experienced about a 28% reduction in pain severity.
The safety profile of pregabalin was consistent with previous fibromyalgia trials and the drug’s current product labeling. Treatment-emergent adverse events were reported by 77.3% of patients on pregabalin and 59.9% for the placebo group. There were four serious adverse events that were not considered related to the treatment; three of which occurred with pregabalin and one with placebo. Our analysis also demonstrated that 6.1% of participants discontinued pregabalin, and 3.4% discontinued placebo due to adverse events.
The results of our analysis indicate that fibromyalgia patients with comorbid depression who are on a stable dose of an antidepressant can benefit significantly with pregabalin. This treatment correlated with significantly lower pain severity when compared with placebo. With pain reduction occurring early and being maintained throughout the study, this represents an important potential strategy for clinicians to consider when managing fibromyalgia and comorbid depression.