Abstract

Gian Maria Pacifici*

ABSTRACT

Naproxen is a propionic acid derivative, is available in the United States, and naproxen is indicated for juvenile and rheumatic arthritis, osteoarthritis, ankylosing spondylitis, pain, primary dysmenorrhoea, tendinitis, bursitis, and acute gout. Naproxen is supplied as tablets, delayed-release tablets, extended-release tablets, gelcaps, and caplets and as oral suspension and suppositories. Naproxen is absorbed fully after oral administration and more slowly after rectal administration. Naproxen has been found efficacy and safe and the prophylaxis and treatment with naproxen and the trials conducted with naproxen have been reviewed. The metabolism of naproxen has been studied in-vitro using human liver microsomes and naproxen is oxidized into 9-O-desmethyl-naproxen by CYP2C9 and by CYP1A2 and naproxen is also conjugated with glucuronic acid by UGT2B7. The pharmacokinetics of naproxen have been studied in 8 patients with rheumatoid arthritis, aged 62+3 years, and in 6 healthy volunteers aged 24+3 years. The peak concentration of naproxen is 79+12 and 110+7 μg/ml (P-value < 0.0001) in patients and healthy volunteers, respectively, and the elimination half-life of naproxen in about 10 hours in patients and in healthy volunteers. Naproxen is bound to plasma protein for 99% and the plasma protein concentration is lower in patients than in healthy volunteers consequently all pharmacokinetic parameters of unbound naproxen are different in patient and adult volunteers. The toxicity induced by naproxen has been reviewed. The aim of this study is to review naproxen efficacy and safely, prophylaxis, treatment, trials conducted with naproxen, and naproxen metabolism, pharmacokinetics, and toxicity induced by naproxen.