Comparison of the antiinflammatory efficacy of chondroitin sulfate and diclofenac sodium in patients with knee osteoarthritis

Objective. To assess the clinical efficacy of chondroitin sulfate (CS) in comparison with the nonsteroidal antiinflammatory drug (NSAID) diclofenac sodium (DS) in a medium/longterm clinical study in patients with knee osteoarthritis (OA). Methods. This was a randomized, multicenter, double blind, double dummy study, 146 patients with knee OA were recruited into 2 groups, During the first month, patients in the NSAID group were treated with 3 x 50 mg DS tablets/day and 3 x 400 mg placebo (for CS) sachets; from Month 2 to Month 3, patients were given placebo sachets alone. In the CS group, patients were treated with 3 x 50 mg placebo (for diclofenac) tablets/day and 3 x 400 mg CS sachets/day during the first month; from Month 2 to Month 3, these patients received only CS sachets. Both groups were treated with 3 x 400 mg placebo sachets from Month 4 to Month 6. Clinical efficacy was evaluated by assessing the Lequesne Index, spontaneous pain (using the Huskisson visual analog scale), pain on load (using a 4 point ordinal scale), and paracetamol consumption. Results. Patients treated with the NSAID showed prompt and plain reduction of clinical symptoms, which, however, reappeared after the end of treatment; in the CS group, the therapeutic response appeared later in time but lasted for up to 3 months after the end of treatment. Conclusion. CS seems to have slow but gradually increasing clinical activity in OA; these benefits last for a long period after the end of treatment.