Double-blind comparison of etodolac SR and diclofenac SR in the treatment of patients with degenerative joint disease of the knee.

An on-going multi-centre, double-blind, parallel-group study is being carried out to compare the efficacy and tolerability of sustained-release (SR) formulations of etodolac and diclofenac in patients with degenerative joint disease (osteoarthritis) of the knee. An interim analysis of the findings has been made for 64 patients from two centres which have now completed their part in the study. Thirty-two patients were randomly assigned to receive 600 mg etodolac SR once daily for 4 weeks; the remaining 32 patients received 100 mg diclofenac SR. Primary efficacy assessments rated on a 5-point categorical scale were patient and physician overall assessments of the patient's condition, night pain and pain intensity. Secondary efficacy parameters included weight-bearing pain, stiffness duration, joint tenderness on pressure, degree of swelling and erythema, degree of knee flexion and time to walk 15 metres. The results showed that for both etodolac SR and diclofenac SR treatment groups there was an improvement from baseline in all efficacy parameters at the last visit and no statistically significant difference was observed between treatments. However, although not statistically significant, the improvement rate in the patient's condition at Week 2 was slightly greater in the etodolac SR treatment group, suggesting that improvement may occur more rapidly with etodolac SR than with diclofenac SR. With regard to tolerability, 5 patients in the etodolac SR treatment group and 3 in the diclofenac SR group withdrew from the study because of adverse reactions. Two events (dyspepsia and mouth ulceration) in the etodolac SR group and 4 events (headache, glossitis, depression and insomnia) in the diclofenac SR group were considered to be definitely drug-related. Dyspepsia was reported by 3 patients (1 withdrawal) treated with etodolac SR and by 4 patients (2 withdrawals) treated with diclofenac SR. A statistically significant decrease was observed in haemoglobin and haematocrit values after 4 weeks of treatment in the diclofenac SR group, but this was not considered to be clinically important. In addition, there were no clinically significant changes in blood chemistry and urinalysis for either treatments. In conclusion, the results of the present study indicate that 600 mg etodolac SR once daily for 4 weeks is effective in the treatment of patients with degenerative joint disease of the knee, as is 100 mg diclofenac SR. In addition, both drugs have comparable tolerability profiles.