Blood Glutathione Peroxidase Activity in Patients with Osteoarthritis Treated with Oxicams

The main objective of this study was the comparison of the influence for three non-steroidal anti-inflammatory drugs (NSAIDs) belonging to the oxicam class, namely piroxicam and tenoxicam, as non-selective inhibitors of cyclooxygenase (COX), and meloxicam, a selective COX-2 inhibitor, on glutathione peroxidase (GPx) activity in patients with osteoarthritis of the knee. Thirty adult subjects clinically and radiographically diagnosed with knee osteoarthritis, who were not previously subjected to any treatment, were enrolled. They were divided in three groups, each with ten subjects. The serum levels of GPx were assessed at baseline and after twenty days of treatment. The first group received piroxicam at a dose of 20 mg orally daily, the second group was treated with tenoxicam at a dose of 20 mg orally daily, and in the third group meloxicam was administrated in a dose of 15 mg orally daily. After the treatment, it was observed an increase of the GPx activity in all groups. The group treated with meloxicam presented the highest rise in the GPx level (p = 0.052). The 20 days study concerning the effects of treatment with NSAIDs belonging to the oxicam class in subjects with knee osteoarthritis revealed that piroxicam, tenoxicam and meloxicam determined a slightly increase in the GPx activity, although this rise had no statistical significance.