Dược Động Học :
▧ Absorption :
The absolute bioavailability of rosiglitazone is 99%. Peak plasma concentrations are observed about 1 hour after dosing. Administration of rosiglitazone with food resulted in no change in overall exposure (AUC), but there was an approximately 28% decrease in Cmax and a delay in Tmax (1.75 hours). These changes are not likely to be clinically significant; therefore, rosiglitazone may be administered with or without food. Maximum plasma concentration (Cmax) and the area under the curve (AUC) of rosiglitazone increase in a dose-proportional manner over the therapeutic dose range.
▧ Volume of Distribution :
* 17.6 L [oral volume of distribution Vss/F]
* 13.5 L [population mean, pediatric patients]
▧ Protein binding :
99.8% bound to plasma proteins, primarily albumin.
▧ Metabolism :
Hepatic. Rosiglitazone is extensively metabolized in the liver to inactive metabolites via N-demethylation, hydroxylation, and conjugation with sulfate and glucuronic acid. In vitro data have shown that Cytochrome (CYP) P450 isoenzyme 2C8 (CYP2C8) and to a minor extent CYP2C9 are involved in the hepatic metabolism of rosiglitazone.
▧ Route of Elimination :
Following oral or intravenous administration of [14C]rosiglitazone maleate, approximately 64% and 23% of the dose was eliminated in the urine and in the feces, respectively.
▧ Half Life :
3-4 hours (single oral dose, independent of dose)
▧ Clearance :
* Oral clearance (CL) = 3.03 ± 0.87 L/hr [1 mg Fasting]
* Oral CL = 2.89 ± 0.71 L/hr [2 mg Fasting]
* Oral CL = 2.85 ± 0.69 L/hr [8 mg Fasting]
* Oral CL = 2.97 ± 0.81 L/hr [8 mg Fed]
* 3.15 L/hr [Population mean, Pediatric patients]