A double-blind study to compare the efficacy and tolerance of dexibuprofen 900 mg with 150 mg diclofenac sodium in patients with painful osteoarthritis of the knee

In this randomized double-blind, parallel-group study the efficacy of 300 mg oral dexibuprofen three times daily and 50 mg oral diclofenac sodium three times daily was tested for equivalence in 110 patients with painful osteoarthritis of the knee. During the 15-day treatment period the functional index for knee osteoarthritis according to Lequesne was improved under dexibuprofen by a mean of 7.4 and by a mean of 7.3 under treatment with diclofenac sodium. The test for equivalence by one-sided Wilcoxon-Mann-Whitney test shows equivalent efficacy of dexibuprofen by a Mann-Whitney-statistic of 0.505 and 0.415 as its lower boundary of the 95% confidence interval. The descriptive analysis of secondary criteria such as intensity of pain, rest pain, pain at beginning, nocturnal pain, tenderness, restriction of movement, handicap, subjective estimation of disease progression, as well as global judgement of efficacy and tolerance by investigator and patient confirm equivalence of both preparations. The pooled analysis of all parameters, tolerability included, by a Mann-Whitney-statistic of 0.520 with the lower boundary of the 95% confidence interval of 0.467 shows equivalence of both drugs with a trend to superiority of dexibuprofen due to its better tolerability. 7.3% of the patients on dexibuprofen and 14.5% of the patients on diclofenac sodium dropped out because of side-effects.