title: [6-methoxy-2-naphthylacetic acid level in plasma, synovial fluid and adjacent tissue in patients with rheumatoid arthritis or gonarthroses after a 4-day therapy with nabumetone (Arthaxan)].
abstract: The concentration of 6-methoxy-2-naphthyl acetic acid (6-MNA) in plasma, synovial fluid, synovial tissue and fibrous capsule tissue was determined in an open study with 20 patients scheduled for knee joint surgery after oral treatment with nabumetone (Arthaxan) under steady state conditions. 6-MNA is the principal metabolite of the prodrug nabumetone arising from an extensive first-pass metabolism in the liver. The patients suffering from rheumatoid arthritis (n = 12) or osteoarthritis stage III or IV (n = 8) received a daily dose of 1 g nabumetone nocte starting 4 days prior to surgery. On day 1 an additional loading dose of 1 g nabumetone was given in the morning. At the time of surgery (day 5) simultaneously blood and synovial fluid was aspirated and after medial opening of the knee joint biopsies of synovial tissue and fibrous capsule tissue were taken. The samples were analysed employing HPLC. After 4 days of treatment mean 6-MNA concentration in plasma was 40.76 micrograms/ml, in synovial fluid 34.79 micrograms/ml, in synovial tissue 19.33 micrograms/g and in fibrous capsule tissue 11.43 micrograms/g. Under steady state conditions mean synovial fluid levels of 6-MNA were higher than after application of a single dose.
authors.affiliation: Abteilung für Rheumaorthopädie, Nordwestdeutsches Zentrum für Rheumatologie, Sendenhorst.
authors.forename: R K
authors.initials: RK
authors.lastname: Miehlke
authors.forename: S
authors.initials: S
authors.lastname: Schneider
authors.forename: F
authors.initials: F
authors.lastname: Sörgel
authors.forename: P
authors.initials: P
authors.lastname: Muth
authors.forename: F
authors.initials: F
authors.lastname: Henschke
authors.forename: M
authors.initials: M
authors.lastname: Fedder
mesh_terms: D000328:Adult; D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal; D001172:Arthritis, Rheumatoid / Q000097:blood / Q000188:drug therapy*; D001682:Biological Availability; D001711:Biotransformation; D002074:Butanones / Q000493:pharmacokinetics / Q000627:therapeutic use*; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D000077430:Nabumetone; D009280:Naphthaleneacetic Acids / Q000493:pharmacokinetics*; D010003:Osteoarthritis / Q000097:blood / Q000188:drug therapy*; D013582:Synovial Fluid / Q000378:metabolism*
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D002074:Butanones; D009280:Naphthaleneacetic Acids; C044612:6-methoxy-2-naphthylacetic acid; D000077430:Nabumetone
vernacular_title: 6-Methoxy-2-Naphthylessigsäure-Spiegel in Plasma, Synovialflüssigkeit und umliegenden Geweben bei Patienten mit rheumatoider Arthritis oder Gonarthrosen nach 4tägiger Therapie mit Nabumeton (Arthaxan).