Enteric-coated and plain naproxen tablets in osteoarthritis; tolerability and efficacy

The aim of this 8 week study, was to compare the tolerability and efficacy of enteric-coated (ECT) and plain naproxen tablets (PT). Ninety eight patients (mean age 66 years) with osteoarthritis were included in a randomized, multi-centre, double-blind, cross-over study. Response variables were monitored at 2 week intervals for the duration of the study. Sixteen patients withdrew from the study, eight because of gastrointestinal (GI) adverse events (ECT 5, PT3). There was no significant difference in patients preference. Eighteen patients reported GI adverse events only on PT compared to 9 on ECT (n.s.). In the first treatment period the severity of adverse events was significantly less on ECT (P = 0.015). Both enteric-coated and plain naproxen tablets were effective and well tolerated. In conclusion, the study did not show any clinical significant difference in tolerability or efficacy between the formulations in osteoarthritis of the knee and/or the hip, although some of the variables did show statistical significant difference or tendency in favour of the enteric coated tablets.