Double-blind, randomized, controlled, crossover trial of pregabalin for neurogenic claudication

Objectives: To test the effects of pregabalin on the induction of neurogenic claudication. Methods: This study was a randomized, double-blind, active placebo-controlled, 2-period, crossover trial. Twenty-nine subjects were randomized to receive pregabalin followed by active placebo (i.e., diphenhydramine) or active placebo followed by pregabalin. Each treatment period lasted 10 days, including a 2-step titration. Periods were separated by a 10-day washout period, including a 3-day taper phase after the first period. The primary outcome variable was the time to first moderate pain symptom (Numeric Rating Scale score >= 4) during a 15-minute treadmill test (T-first). Secondary outcome measures included pain intensity at rest, pain intensity at the end of the treadmill test, distance walked, and validated self-report measures of pain and functional limitation including the Roland-Morris Disability Questionnaire, modified Brief Pain Inventory-Short Form, Oswestry Disability Index, and Swiss Spinal Stenosis Questionnaire. Results: No significant difference was found between pregabalin and active placebo for the time to first moderate pain symptom (difference in median T-first = -1.08 [95% confidence interval -2.25 to 0.08], p = 0.61). In addition, none of the secondary outcome measures of pain or functional limitation were significantly improved by pregabalin compared with active placebo. Conclusions: Pregabalin was not more effective than active placebo in reducing painful symptoms or functional limitations in patients with neurogenic claudication associated with lumbar spinal stenosis. Classification of evidence: This study provides Class I evidence that for patients with neurogenic claudication, compared with diphenhydramine, pregabalin does not increase the time to moderate pain during a treadmill test.