title: Pharmacokinetics/pharmacodynamics of ketoconazole-prednisolone interaction.
abstract: Ketoconazole is commonly used in patients with fungal infections during immunosuppressive therapy with prednisolone. Ketoconazole inhibits mixed function oxidases, enzymes responsible for the catabolism of prednisolone, and might, by that mechanism, increase prednisolone concentrations and thus, the immunosuppressive effect of prednisolone. On the other hand, ketoconazole has been found to bind to the glucocorticoid receptor and, thereby, to function as a glucocorticoid antagonist in cultured cell preparations. In order to establish whether ketoconazole enhances or attenuates the immunosuppressive effect of prednisolone, the influence of ketoconazole on the kinetics of prednisolone and on the delayed hypersensitivity response was assessed in mice. Ketoconazole increased prednisolone concentrations, measured by high pressure liquid chromatography, in mice given a single dose of prednisolone or a continuous prednisolone treatment for 17 days. At four different doses of prednisolone administered for 17 days, the glucocorticoid therapy-associated inhibition of the delayed hypersensitivity response to keyhole limpet hemocyanin was enhanced by ketoconazole. Thus, coadministration of ketoconazole with prednisolone increases the exposure to the steroid and enhances the immunosuppressive effect.
authors.affiliation: Division of Molecular Biology and Biochemistry, University of Berne, Switzerland.
authors.forename: B
authors.initials: B
authors.lastname: Ulrich
authors.forename: F J
authors.initials: FJ
authors.lastname: Frey
authors.forename: R F
authors.initials: RF
authors.lastname: Speck
authors.forename: B M
authors.initials: BM
authors.lastname: Frey
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004347:Drug Interactions; D006433:Hemocyanins / Q000633:toxicity; D006968:Hypersensitivity, Delayed / Q000139:chemically induced / Q000188:drug therapy; D007654:Ketoconazole / Q000493:pharmacokinetics / Q000494:pharmacology* / Q000627:therapeutic use; D008297:Male; D051379:Mice; D011239:Prednisolone / Q000097:blood / Q000493:pharmacokinetics / Q000494:pharmacology*; D011241:Prednisone / Q000097:blood
chemical_list: D006433:Hemocyanins; D011239:Prednisolone; C032808:keyhole-limpet hemocyanin; D007654:Ketoconazole; D011241:Prednisone