ISSN:
1432-1041
Keywords:
rifampicin
;
antipyrine
;
3-hydroxymethylantipyrine
;
4-hydroxyantipyrine
;
norphenazone
;
cytochrome P-450
Source:
Springer Online Journal Archives 1860-2000
Topics:
Chemistry and Pharmacology
,
Medicine
Notes:
Summary Antipyrine is oxidised to three main metabolites in man. There is evidence that the different metabolites are products of different forms of cytochrome P-450. The effect of rifampicin administration for two weeks on the rates of formation of these metabolites was investigated in healthy volunteers. Rifampicin increased antipyrine clearance and shortened its half-life. Two weeks after stopping rifampicin the induction had largely been reversed. Clearance to all three metabolites was increased by rifampicin. Clearance to 3-hydroxymethylantipyrine was increased from 7.8±0.9 ml/min to 13.3±1.3 ml/min, to norphenazone from 5.8±0.6 ml/min to 19.3±2.1 ml/min and to 4-hydroxyantipyrine from 14.3±2.2 ml/min to 21.9±3.9 ml/min. Thus clearance to norphenazone was increased to a much greater extent than to either of the other two metabolites. It is concluded that this provides evidence for the involvement of at least two different forms of cytochrome P-450 in antipyrine metabolism in man.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00637517
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