To examine the effects of the two newest monophasic oral contraceptives on liver microsomal drug metabolism, plasma kinetics and urinary metabolite excretion of antipyrine, a model substrate for liver microsomes, were evaluated. Plasma lipid and lipoprotein levels, and in particular the high-density lipoprotein subfractions, were also monitored in view of their apparent regulation by a P450-dependent system. Ten healthy volunteers were treated with each contraceptive for a period of 3 months in a crossover trial. Both contraceptives significantly reduced antipyrine clearance by 34.6% (gestodene) and 43.3% (desogestrel) by impairing the oxidative metabolism, particularly to the 4-hydroxy and 3-hydroxymethyl metabolites, with little difference between the two associations. In addition, with both a comparable highly significant rise of plasma triglyceride levels, apolipoproteins A-1 and A-11 and the high-density lipoprotein-3 subfraction was observed. Treatment with these new monophasic contraceptives may reduce the metabolism of concomitantly given drugs undergoing oxidative transformations.
INHIBITION OF ANTIPYRINE METABOLISM BY LOW-DOSE CONTRACEPTIVES WITH GESTODENE AND DESOGESTREL / F. PAZZUCCONI, B. MALAVASI, G. GALLI, G. FRANCESCHINI, L. CALABRESI, C. SIRTORI. - In: CLINICAL PHARMACOLOGY & THERAPEUTICS. - ISSN 0009-9236. - 49:3(1991), pp. 278-284.
INHIBITION OF ANTIPYRINE METABOLISM BY LOW-DOSE CONTRACEPTIVES WITH GESTODENE AND DESOGESTREL
F. PAZZUCCONIPrimo
;G. FRANCESCHINI;L. CALABRESIPenultimo
;C. SIRTORIUltimo
1991
Abstract
To examine the effects of the two newest monophasic oral contraceptives on liver microsomal drug metabolism, plasma kinetics and urinary metabolite excretion of antipyrine, a model substrate for liver microsomes, were evaluated. Plasma lipid and lipoprotein levels, and in particular the high-density lipoprotein subfractions, were also monitored in view of their apparent regulation by a P450-dependent system. Ten healthy volunteers were treated with each contraceptive for a period of 3 months in a crossover trial. Both contraceptives significantly reduced antipyrine clearance by 34.6% (gestodene) and 43.3% (desogestrel) by impairing the oxidative metabolism, particularly to the 4-hydroxy and 3-hydroxymethyl metabolites, with little difference between the two associations. In addition, with both a comparable highly significant rise of plasma triglyceride levels, apolipoproteins A-1 and A-11 and the high-density lipoprotein-3 subfraction was observed. Treatment with these new monophasic contraceptives may reduce the metabolism of concomitantly given drugs undergoing oxidative transformations.Pubblicazioni consigliate
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