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 (Tfirst). 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 Tfirst = -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.