title: Investigation of drug-drug interaction via mechanism-based inhibition of cytochrome P450 3A by macrolides in dexamethasone-treated female rats.
abstract: The in vitro and in vivo inhibition of cytochrome P450 (CYP) 3A with mechanism-based inhibition (MBI) by macrolides was investigated using dexamethasone-treated female rats (DEX-female rats). In the in vitro CYP inhibition studies using erythromycin (ERM) and clarithromycin (CAM), similar inhibition responses were observed between human and DEX-female rat liver microsomes, however, there were fewer effects in intact male rats. The ex vivo study showed that midazolam (MDZ) metabolism in liver microsomes of DEX-female rats was reduced by ERM administration and the inhibitory effect was increased with increasing ERM doses, indicating that metabolite intermediate complex formation caused irreversible inhibition of CYP3A activity in DEX-female rats as well as in humans. In the in vivo studies, ERM and CAM significantly increased the area under the plasma concentration-time curve of MDZ and decreased the total clearance in DEX-female rats. It was concluded that the DDIs via MBI of CYP3A following macrolide administration in humans could be reproduced in female rats, suggesting that DEX-female rats can serve as an in vivo model for assessing this DDI in humans.
authors.affiliation: Drug Metabolism and Pharmacokinetics, Drug Developmental Research Laboratories, Shionogi & Co., Ltd, Toyonaka, Osaka, Japan. takushi.kanazu@shionogi.co.jp
authors.forename: Takushi
authors.initials: T
authors.lastname: Kanazu
authors.forename: Norihito
authors.initials: N
authors.lastname: Sato
authors.forename: Kyoko
authors.initials: K
authors.lastname: Kadono
authors.forename: Akira
authors.initials: A
authors.lastname: Touchi
authors.forename: Yuri
authors.initials: Y
authors.lastname: Takeda
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Yamaguchi
authors.forename: Takahiko
authors.initials: T
authors.lastname: Baba
mesh_terms: D000818:Animals; D019540:Area Under Curve; D017291:Clarithromycin / Q000494:pharmacology*; D051544:Cytochrome P-450 CYP3A / Q000378:metabolism; D065692:Cytochrome P-450 CYP3A Inhibitors; D003907:Dexamethasone / Q000008:administration & dosage / Q000494:pharmacology; D004347:Drug Interactions; D004917:Erythromycin / Q000494:pharmacology*; D005260:Female; D006801:Humans; D008297:Male; D008862:Microsomes, Liver / Q000187:drug effects / Q000378:metabolism; D008874:Midazolam / Q000378:metabolism*; D008954:Models, Biological; D051381:Rats; D012737:Sex Factors; D013045:Species Specificity
chemical_list: D065692:Cytochrome P-450 CYP3A Inhibitors; D004917:Erythromycin; D003907:Dexamethasone; D051544:Cytochrome P-450 CYP3A; D017291:Clarithromycin; D008874:Midazolam