Efficacy of rofecoxib, celecoxib, and acetaminophen in osteoarthritis of the knee - A randomized trial

Context Osteoarthritis (OA) is often treated with nonsteroidal ant-inflammatory drugs (NSAIDs), acetaminophen, or specific inhibitors of cyclooxygenase 2 (COX-2). Objective To assess the relative therapeutic efficacy of rofecoxib, celecoxib, and acetaminophen in adults with OA. Design and Setting Randomized, parallel-group, double-blind trial, conducted from June 1999 to February 2000, in 29 clinical centers in the United States. Patients Three hundred eighty-two patients aged at least 40 years who had OA of the knee that was previously treated with NSAIDs or acetaminophen. Interventions Patients were randomly assigned to receive rofecoxib, 12.5 mg/d (n=96); rofecoxib 25 mg/d (n=95); celecoxib, 200 mg/d (n=97); or acetaminophen, 4000 mg/d (n=94) for 6 weeks. Main Outcome Measures Assessments over days 1 to 6 and over 6 weeks included pain on walking, night pain, pain at rest, and morning stiffness as measured on a Western Ontario McMaster Universities Osteoarthritis Index (100-mm visual analog scale [VAS]) and global response to therapy compared among 4 treatment groups. Results 79% of patients completed the study, More patients treated with acetaminophen discontinued early due to lack of efficacy than patients treated with COX-2 inhibitors (31% vs 18%-19%). Efficacy assessed in the first 6 days of therapy showed greatest response to rofecoxib, 25 mg/d, followed by rofecoxib, 12.5 mg/d, celecoxib, and acetaminophen, respectively, in terms of relief of pain on walking (-32.2, -29.0, -26.4, and -20.6 mm change on the VAS; P less than or equal to .04 for all others vs acetaminophen; P=.05 for 25-mg rofecoxib vs celecoxib), rest pain (-21.8, -18.6, -15.5, and -12.5 mm; P less than or equal to .02 for either dose of rofecoxib vs acetaminophen and P=.02 for rofecoxib, 25 mg/d, vs celecoxib), night pain (-25.2, -22.0, -18.7, and -18.8 mm; P=.04 for rofecoxib, 25 mg/d, vs both acetaminophen and celecoxib), and morning stiffness (-30.4,-28.4,-25.7, and -20.9 mm; P less than or equal to .02 for either dose of rofecoxib vs acetaminophen). Over 6 weeks, rofecoxib, 25 mg/d, provided greatest response for night pain (P<.002 vs celecoxib and P=.006 vs acetaminophen and P=.02 vs rofecoxib, 12.5 mg/d), composite pain subscale (P<less than or equal to>.03 vs all other treatments), stiff ness subscale (P less than or equal to .04 vs celecoxib and acetaminophen), and physical function subscale (P=.001 vs acetaminophen). Global responses over 6 weeks showed a similar pattern (good or excellent response at week 6: 60%, 56%, 46%, and 39%, respectively; P less than or equal to .03 for rofecoxib, 25 mg/d, vs celecoxib and acetaminophen; P=.02 for rofecoxib, 12.5 mg/d, vs acetaminophen). All treatments were generally safe and well tolerated. Conclusion Rofecoxib, 25 mg/d, provided efficacy advantages over acetaminophen, 4000 mg/d, celecoxib, 200 mg/d, and rofecoxib, 12.5 mg, for symptomatic knee OA.