RESUMO
STUDY DESIGN: Randomized, double-blind, placebo-controlled, single-dose crossover study. OBJECTIVE: To test the analgesic efficacy of oxymorphone hydrochloride (OH) and propoxyphene/acetaminophen (PA) for patients with neurogenic claudication associated with lumbar spinal stenosis. SUMMARY OF BACKGROUND DATA: Although opioids are often prescribed for neurogenic claudication, no randomized controlled studies support their efficacy for this condition. Patients with neurogenic claudication are generally excluded from clinical trials or included with patients who have nonspecific chronic low back pain, yielding a heterogeneous study population with very different pathophysiologies and clinical presentations. METHODS: Participants received a single dose of each of the 3 treatments in random order. Treatments were separated by at least 3-day washout periods. The primary outcome variable was the time to first treadmill walking-induced moderate pain (≥4 out of 10 on a Numeric Rating Scale) (Tfirst) assessed 90 minutes after treatment administration. Secondary outcome measures included patient global assessment of low back pain, Roland-Morris Disability Questionnaire, Modified Brief Pain Inventory-Short Form, Oswestry Disability Index, and Swiss Spinal Stenosis Questionnaire. RESULTS: The study was prematurely terminated because of the removal of PA from the US market. Twenty-four patients were randomized; 21 completed all 3 treatment periods. There were no significant differences among the treatment groups with respect to the median Tfirst (OH-placebo: median [98.3% confidence limits]=-0.25 min [-6.54, 5.00]; PA-placebo: 0.02 min [-7.65, 4.90]; OH-PA: -0.27 min [-5.56, 6.66]). CONCLUSION: This trial failed to demonstrate a benefit of OH or PA in patients experiencing neurogenic claudication. Considering the potential negative side effects of chronic opioid use, additional research is necessary to evaluate the efficacy of sustained opioid treatment specifically for neurogenic claudication. LEVEL OF EVIDENCE: 2.