N-acetylation and oxidative capacity in aged volunteers determined with sulfamethazine and antipyrine.
The elimination of antipyrine (AP 15 mg/kg) and sulfamethazine (SM 500 mg) was measured in healthy volunteers of rapid and slow acetylator phenotype. Nineteen males were 20-32 years of age, 11 males and 6 females between 62-86 years of age. Apparent volume of distribution of AP was reduced in advanced age independent of the acetylator status of the individuals. Total body clearance was significantly lower and half-time and mean residence time were higher only in slow but not in rapid acetylators. In the elderly of both phenotypes, the acetylation ratios of SM were significantly enhanced. Renal and metabolic clearance were decreased and AUC-values of SM and its acetylated metabolite were increased in slow but unchanged in rapid acetylators. Physiological peculiarities of distribution and renal excretion of SM and its acetylated metabolite in advanced age may have caused the contradictory results.
Siegmund
W
W
Department of Clinical Pharmacology, Ernst-Moritz-Arndt-University of Greifswald, Germany.
Franke
G
G
Wulkow
R
R
Hanke
W
W
Thonack
R
R
D000107:Acetylation; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000983:Antipyrine / Q000097:blood / Q000493:pharmacokinetics*; D005260:Female; D006207:Half-Life; D006801:Humans; D008297:Male; D008657:Metabolic Clearance Rate; D008875:Middle Aged; D010641:Phenotype; D013418:Sulfamethazine / Q000097:blood / Q000493:pharmacokinetics* / Q000652:urine
D013418:Sulfamethazine; D000983:Antipyrine