title: The effect of age on piroxicam disposition in rheumatoid arthritis.
abstract: The disposition of piroxicam in 23 patients with rheumatoid arthritis (9 males, 14 females, aged 27-79) was studied over 6 weeks using the standard oral dose of 20 mg daily. Clinical status was monitored using standard methods. The mean piroxicam steady state plasma concentration (Css) averaged 9.2 +/- 4.4 micrograms/ml, the majority of which was highly protein bound (1.4 +/- 0.5% unbound). Total plasma clearance (CL/F) of piroxicam was 1.85 +/- 0.81 ml/min and the half life (t1/2) was 53.0 +/- 24.2 h. There was wide intersubject variability in the kinetics of piroxicam and its major metabolite 5'-hydroxypiroxicam. Piroxicam CL/F, t1/2 and Css were modestly correlated with patient age. Clinical effects did not appear to be related to piroxicam plasma levels.
authors.affiliation: College of Medicine and Pharmacy, University of Saskatchewan, Saskatoon, Canada.
authors.forename: K L
authors.initials: KL
authors.lastname: Blocka
authors.forename: C J
authors.initials: CJ
authors.lastname: Richardson
authors.forename: S M
authors.initials: SM
authors.lastname: Wallace
authors.forename: S G
authors.initials: SG
authors.lastname: Ross
authors.forename: R K
authors.initials: RK
authors.lastname: Verbeeck
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism*; D000893:Anti-Inflammatory Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000378:metabolism* / Q000503:physiopathology; D001798:Blood Proteins / Q000378:metabolism; D005260:Female; D006706:Homeostasis; D006801:Humans; D008297:Male; D008875:Middle Aged; D009994:Osmolar Concentration; D010894:Piroxicam / Q000097:blood / Q000493:pharmacokinetics* / Q000627:therapeutic use; D012720:Severity of Illness Index; D013582:Synovial Fluid / Q000032:analysis; D013997:Time Factors
chemical_list: D000893:Anti-Inflammatory Agents; D001798:Blood Proteins; D010894:Piroxicam