Nabumetone pharmacokinetics and molecular data

Pharmacokinetics
General Plasma concentrations of 6MNA Food Aluminum-containing Antacid

General
After oral administration, approximately 80% of a radiolabeled dose of nabumetone is found in the urine, indicating that nabumetone is well absorbed from the gastrointestinal tract. Nabumetone itself is not detected in the plasma because, after absorption, it undergoes rapid biotransformation to the principal active metabolite, 6-methoxy-2-naphthylacetic acid (6MNA). Approximately 35% of a 1,000-mg oral dose of nabumetone is converted to 6MNA and 50% is converted into unidentified metabolites which are subsequently excreted in the urine. Following oral administration of RELAFEN, 6MNA exhibits pharmacokinetic characteristics that generally follow a one-compartment model with first order input and first order elimination. Return to top

Plasma concentrations of 6MNA
Steady-state plasma concentrations of 6MNA are slightly lower than predicted from single-dose data. This may result from the higher fraction of unbound 6MNA which undergoes greater hepatic clearance. Return to top

Food
Coadministration of food increases the rate of absorption and subsequent appearance of 6MNA in the plasma but does not affect the extent of conversion of nabumetone into 6MNA. Peak plasma concentrations of 6MNA are increased by approximately one third. Return to top

Aluminum-containing Antacid
Coadministration with an aluminum-containing antacid had no significant effect on the bioavailability of 6MNA. Return to top