Superoxide dismutase (orgotein for injection) has been used in managing osteoarthritis for more than seven years in Europe; however, well-controlled studies to establish an optimum dosage regimen have not been conducted. In this study, three orgotein dose/regimens were compared with placebo in terms of efficacy, safety, and duration of effect in patients with active osteoarthritis of the knee.
A total of 139 patients with osteoarthritis of the knee were enrolled in the study. Nonsteroidal anti-inflammatory agents were withdrawn to induce a flare of disease activity. Patients were then randomly assigned to receive one intra-articular injection of either placebo or orgotein (8 mg to 32 mg) each week for three weeks. Both investigators and patients evaluated disease activity and adverse experiences at a series of follow-up visits for three months.
Orgotein was effective in reducing symptoms of osteoarthritis for up to three months after treatment; 16 mg given twice was the most effective and most best-tolerated regimen. Discomfort at the injection site was drug related, although this effect also occurred occasionally after injection of placebo.
The long-lasting effects of intra-articular superoxide dismutase contribute to a favorable risk-benefit ratio and support the importance of the free-radical anion, superoxide (O2-), in the biochemical pathology of osteoarthritis.