Objective: To evaluate pregabalin in central neuropathic pain associated with spinal cord injury.
Methods: A 12-week, multicenter study of patients randomized to either flexible-dose pregabalin 150 to 600 mg/day (n = 70) or placebo (n = 67), administered BID. Patients were allowed to remain on existing, stable pain therapy. The primary efficacy variable was the endpoint mean pain score, derived from patients' last 7 days daily pain diary entries. Key secondary endpoints included pain responder rates, the SF-MPQ, sleep interference, mood, and the patient global measure of change.
Results: The mean baseline pain score was 6.54 in the pregabalin group and 6.73 in the placebo group. The mean endpoint pain score was lower in the pregabalin group (4.62) than the placebo group (6.27; p < 0.001), with efficacy observed as early as week 1 and maintained for the duration of the study. The average pregabalin dose after the 3-week stabilization phase was 460 mg/day. Pregabalin was significantly superior to placebo in endpoint assessments on the SF-MPQ. The > or =30% and > or =50% pain responder rates were higher with pregabalin than placebo (p < 0.05). Pregabalin was associated with improvements in disturbed sleep (p < 0.001) and anxiety (p < 0.05), and more patients reported global improvement at endpoint in the pregabalin group (p < 0.001). Mild or moderate, typically transient, somnolence and dizziness were the most common adverse events.
Conclusions: Pregabalin 150 to 600 mg/day was effective in relieving central neuropathic pain, improving sleep, anxiety, and overall patient status in patients with spinal cord injury.