A pharmacokinetic study of the active metabolite of nabumetone in young healthy subjects and older arthritis patients.

We have performed a detailed pharmacokinetic study of the plasma concentrations of the major active metabolite of nabumetone, 6-methoxy-2-naphthylacetic acid (6 MNA), attained after a single dose and during chronic administration comparing the results of a group of young healthy volunteers with those of a group of elderly arthritic patients. The latter had higher peak plasma concentrations of 6 MNA and slower rates of elimination but there is no tendency for the drug to accumulate unpredictably in the old. Disease activity also influences plasma concentration, those with more active disease, and lower serum albumin concentrations had lower AUC values.