Pain Changes in Pregabalin-Treated (Lyrica®) Fibromyalgia Patients Associate with Anxiety and Depression Changes

Chronic pain and concomitant anxiety and depressive symptoms are common in fibromyalgia (FM) patients. Three parallel group RCTs found pregabalin to be effective for treating pain in FM patients. These studies also collected anxiety and depressive symptom levels. which were used to explore the possible relationship between pregabalin's effect on pain, anxiety and depressive symptoms in patients with FM. Patients meeting ACR criteria for FM and who had pain VAS score ≥40 mm were followed for 8-14 weeks in 3 randomized, double-blind, placebo-controlled trials. A total of 2022 patients received either 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]). Changes from baseline to endpoint in anxiety and depressive symptom levels were assessed using the Hospital Anxiety and Depression Scales (HADS-A and HADS-D). Pearson correlations were used to explore associations between changes in pain, HADS-A and HADS-D. Pregabalin 300, 450, and 600mg/d but not 150mg/d showed statistically significant improvements in pain compared with placebo (p<0.0001). Pregabalin 450 and 600mg/d showed statistically significant improvements in HADS-A compared with placebo (p<0.01). Results were mixed for HADS-D. Correlations, by treatment, between changes in pain and HADS-A/HADS-D were as follows: 0.44/0.48 (150mg/d), 0.29/0.37 (300mg/d), 0.26/0.34 (450mg/d), and 0.27/0.31 (600mg/d). Adverse events (AEs) were consistent with known side effects of pregabalin; dizziness and somnolence were the most frequently reported AEs for patients who received pregabalin. Changes in pain correlated with changes in anxiety and depression across all treatments for patients with FM. Greatest improvements for all three outcomes were seen in the pregabalin 450mg/d group.

Study funded by Pfizer, Inc