Examine the evidence for a relationship between pregabalin effect on pain and baseline anxiety and depressive symptoms in patients with fibromyalgia (FM).

Chronic pain and concomitant anxiety and depressive symptoms are common in patients with FM, as well as in other chronic pain disorders. Pregabalin was effective for treating pain in FM patients in three parallel group RCTs (105, 1056, 1077) where data for anxiety and depressive symptom levels were collected.

Patients meeting ACR criteria for FM with a pain VAS score ≥40 mm were followed for 8-14 weeks in 3 randomized, double-blind, placebo-controlled trials. Patients (N=2022) received 150, 300, 450 or 600mg/d pregabalin or placebo. The primary efficacy parameter was change in endpoint Mean Pain Score (MPS) (range 0 [no pain]-10[worst possible pain]). Regression analyses evaluated whether changes in pain bore any relation to the baseline Hospital Anxiety and Depression Scales (HADS-A) and (HADS-D) levels.

Pregabalin 300, 450, and 600 mg/d, but not 150 mg/d, showed statistically significant improvements in pain compared with placebo (p<0.0001). For each pregabalin treatment group, improvements in pain at endpoint were not found to have a statistically significant association with baseline levels of anxiety or depressive symptoms. Adverse events (AEs) were consistent with known side effects of pregabalin; dizziness and somnolence, mild to moderate in intensity, were the most frequently reported AEs for pregabalin patients.

Pregabalin treatment demonstrated significant improvements in pain regardless of baseline anxiety or depressive symptom levels for patients with FM.

Study funded by Pfizer, Inc