Safety Profile and Tolerability of Up to 1 Year of Pregabalin Treatment in 3 Open-Label Extension Studies in Patients With Fibromyalgia

Background: Pain relief and an acceptable safety profile have been reported in randomized controlled trials (RCTs) of pregabalin in the treatment of fibromyalgia (FM) for up to 14 weeks. Objective: To evaluate the safety profile and tolerability of pregabalin (75-300 mg BID) treatment for up to 1 year in patients with FM. Methods: Twelve-week data were pooled from 3 open-label extension studies of pivotal RCTs. Study 1 was a 1-year extension of a 13-week RCT, and studies 2 and 3 were 12-week extensions of 14-week RCTs. The 1-year data were separately evaluated. The open-label data are summarized using descriptive statistics. Results: Overall, 1206 patients (92.4% female) with a mean (SD) age of 48.8 (10.7) years received open-label extended pregabalin treatment. A total of 119 of 1206 patients (9.9%) permanently discontinued study participation due to treatment-emergent adverse events (all causality) at 12 weeks (pooled data) and 53 of 429 (12.4%) within 1 year. Consistent with previous RCTs, the most commonly reported treatment-emergent adverse events with open-label pregabalin treatment were dizziness, somnolence, headache, peripheral edema, and increased weight. The highest incidence rates in the pooled 12-week data were for dizziness (214 of 1206; 17.7%) and somnolence (96 of 1206; 8.0%). In ratings of severity (mild, moderate, severe), most were reported as mild to moderate. The mean (SD) change in patient-reported visual analog scale pain scores (0-100) from the open-label baseline to the end of treatment was -21 (30.5) in study 1 (1 year), -26.7 (28.8) in study 2 (12 weeks), and -20.1 (26.8) in study 3 (12 weeks). Conclusions: The data from these extension studies suggest that the adverse event safety profile and tolerability of patients with FM treated with open-label pregabalin (75-300 mg BID) for up to 1 year were stable and were consistent with those of previous studies. ClinicalTrials.gov identifiers: NCT00151528 (A0081057 [study 1]), NCT00282997 (A0081078 [study 2]), and NCT00346034 (A0081101 [study 3]). (Clin Ther. 2012;34:1092-1102) (C) 2012 Elsevier HS Journals, Inc. All rights reserved.