Pregabalin Is Ineffective for Patients with Neurogenic Claudication

Pregabalin and gabapentin are prescribed frequently for pain of sciatica or spinal stenosis, but properly controlled trials are lacking. In this industry-funded, randomized, double-blind crossover trial, researchers tested the efficacy of pregabalin in 26 patients with radiographically confirmed lumbar spinal stenosis and neurogenic claudication for ≥3 months. Enrollment criteria included pain on ambulation but not at rest. On baseline treadmill testing, mean time to a pain score of ≥4 (on a 10-point scale) was 2.5 minutes.

Patients received pregabalin (75 mg) or an “active placebo” (diphenhydramine, 6.25 mg) twice daily initially, with doses doubled after 3 days. (The low-dose diphenhydramine control was chosen to mimic the sedative effects of pregabalin and maximize blinding.) After 10 days of treatment, a 3-day taper, and a 1-week washout period, patients received the opposite treatment. On repeat treadmill testing, no significant differences were found between pregabalin and active-placebo periods in time to onset of a pain score ≥4. One secondary outcome (a standardized disability score) showed greater improvement with active placebo than with pregabalin. Adverse effects were reported more often with pregabalin than with placebo (64% vs. 35%).