Journals of Gerontology Series A: Biological Sciences and Medical Sciences, Vol 53, Issue 1 M14-M19, Copyright © 1998 by The Gerontological Society of America
The effect of age and sex on metabolism and urinary excretion of antipyrine
F Jorquera, M Almar, M Pozuelo, D Sansegundo, M Gonzalez-Sastre and J Gonzalez- Gallego
Gastroenterology Unit, Hospital de Insalud, Leon, Spain.
BACKGROUND: Drug-metabolizing capacity is generally reduced in the elderly.
The purpose of this investigation was to study antipyrine clearance and
metabolite excretion in old subjects of both sexes. METHODS: Saliva
clearance of antipyrine and the production clearances of antipyrine
metabolites were studied in young and elderly volunteers of both sexes.
Seventy-six elderly subjects (mean age 81 years) were compared with a group
of 24 young subjects (mean age 29 years). RESULTS: After oral
administration, salivary antipyrine clearance declined with age in both
males and females, whether or not this variable was corrected for weight,
and antipyrine half-life was significantly prolonged in elderly groups of
either sex. The percentage urinary excretion of the antipyrine metabolites
(hydroxymethylantipyrine, HMA; norantipyrine, NORA; and 4-
hydroxyantipyrine, OHA) was reduced at 48 h in the elderly compared to
young subjects by 23%, 31%, and 10%, respectively, in males, and by 41%,
41%, and 24%, respectively, in females. The formation clearance of HMA was
reduced by 47% in males and by 52% in females. NORA clearance declined by
42 and 56%, respectively, in males and females. A decrease of 30% in males
and 44% in females was observed in OHA clearance. CONCLUSIONS: The findings
suggest that aging leads to altered disposition of antipyrine in both males
and females and that the main metabolic pathways of the compound are not
different in the elderly.
