Efficacy and safety of etodolac and naproxen in patients with osteoarthritis of the knee: a double-blind, placebo-controlled study.

A multicenter, parallel-group, double-blind, randomized, outpatient study compared the efficacy and safety of etodolac versus naproxen in patients with osteoarthritis of the knee. After a washout period free of nonsteroidal anti-inflammatory drugs, 254 patients self-administered etodolac 400 mg (n = 86), naproxen 500 mg (n = 82), or placebo (n = 86) twice daily for 4 weeks. Compliance exceeded 90% in all three groups. Primary efficacy variables improved progressively from baseline in all three groups. The extent of improvement was greater in the etodolac and naproxen groups than in the placebo group (P < or = 0.003), except with respect to target joint tenderness (P = 0.028, etodolac vs placebo; P = 0.013, naproxen vs placebo). There were no statistical differences between active treatment groups (P > 0.1). At end point, twice as many patients responded in the etodolac (59%) and naproxen groups (51%) than in the placebo group (26%; P < or = 0.01). There were no significant between-group differences in the numbers of patients who had an adverse experience, a serious adverse experience, or an adverse experience leading to study discontinuation; there were also no significant between-group differences in the distribution of adverse experiences. There were no unexpected clinical or laboratory experiences. Etodolac 400 mg twice daily was as effective and safe as naproxen 500 mg twice daily and both were superior to placebo in the management of osteoarthritis of the knee.