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

Abstract 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]).