title: [Changes in the pharmacokinetics of theophylline during estrus in rats].
abstract: The influence of menstrual cycle on drug kinetics is not largely documented. Concerning theophylline it was of interest to investigate whether or not the kinetics of this drug is modified throughout the oestrous cycle. Though the kinetics of this drug was assessed in adult Wistar female rats at different stages of the oestrous cycle: proestrous (P), oestrous (O) and diestrus (D). Our preliminary data clearly indicate statistically significant differences (p less than 0.01) of theophylline kinetic parameters such as elimination half-life: 8.70 +/- 0.60 h (P), 4.61 +/- 0.16 h (O) and 5.01 +/- 0.85 h (D), area under concentration versus time curve (AUC): 214.61 +/- 3.58 micrograms.h/ml (P), 128.64 +/- 9.64 micrograms.h/ml (O) and 165.57 +/- 23.86 micrograms.h/ml (D). These results agree with clinical data reported on the influence of estroprogestative drugs on theophylline kinetics in women (higher elimination half-life and lower clearance). In order to explain some of our findings the possible variations of theophylline protein binding and metabolism throughout the oestrous cycle are under investigation.
mesh_terms: D000818:Animals; D004971:Estrus / Q000378:metabolism*; D005260:Female; D007700:Kinetics; D051381:Rats; D011919:Rats, Inbred Strains; D013806:Theophylline / Q000378:metabolism*
chemical_list: D013806:Theophylline
vernacular_title: Modifications de la pharmacocinétique de la théophylline au cours du cycle oestral chez la ratte.