Aceclofenac vs paracetamol in the management of symptomatic osteoarthritis of the knee: a double-blind 6-week randomized controlled trial.

OBJECTIVE: To evaluate the efficacy and tolerability of aceclofenac, 200 mg/day, and paracetamol, 3000 mg/day, in the treatment of osteoarthritis (OA) of the knee.

METHODS: This was a double-blind, parallel-group, multicentre clinical trial involving patients with symptomatic OA of the knee, conducted in Spain. Patients were randomly allocated to aceclofenac 100 mg twice daily (n=82) or paracetamol 1000 mg three times daily (n=86). Patients were assessed at baseline and 6 weeks. Primary efficacy measures were severity of pain (visual analogue scale, VAS), Lequesne OA knee index, and patient's and physician's global assessment of disease activity. Severity of knee pain at rest or walking, stiffness, knee swelling and tenderness, and assessment of health-related quality of life (Health Assessment Questionnaire, Western Ontario and McMaster Universities Osteoarthritis Index, and Short Form 36) were included as secondary endpoints.

RESULTS: Both treatment groups showed significant improvement compared with their baseline values in the four primary endpoints. Mean between-treatment differences favoured aceclofenac over paracetamol on pain (VAS, 7.64 mm [95% confidence interval (CI), 0.44-14.85 mm]), Lequesne OA index (1.41 [95% CI, 0.45-2.36]), and patient's (0.33 [95% CI, 0.06-0.61]) and physician's (0.23 [95% CI, 0.01-0.47]) global assessments. Adverse events were similar for both drugs (paracetamol, 29% patients vs aceclofenac, 32%; P=0.71). Four patients withdrew in each group due to adverse events. Patients tended to prefer aceclofenac to paracetamol (P=0.001), and more treated with paracetamol withdrew from the study due to lack of efficacy (n=8 vs n=1, P=0.035, for paracetamol and aceclofenac, respectively).

CONCLUSION: At 6 weeks, patients with symptomatic OA of the knee showed a greater improvement in pain and functional capacity with aceclofenac than paracetamol with no difference in tolerability.