TY - JOUR T1 - Recovery of CYP3A Phenotype after Kidney Transplantation JF - Drug Metabolism and Disposition JO - Drug Metab Dispos SP - 1260 LP - 1265 DO - 10.1124/dmd.117.078030 VL - 45 IS - 12 AU - Kristine Hole AU - Elisabet Størset AU - Ane Olastuen AU - Tore Haslemo AU - Grete Birkeland Kro AU - Karsten Midtvedt AU - Anders Åsberg AU - Espen Molden Y1 - 2017/12/01 UR - http://dmd.aspetjournals.org/content/45/12/1260.abstract N2 - End-stage renal disease impairs drug metabolism via cytochrome P450 CYP3A; however, it is unclear whether CYP3A activity recovers after kidney transplantation. Therefore, the aim of this study was to evaluate the change in CYP3A activity measured as 4β-hydroxycholesterol (4βOHC) concentration after kidney transplantation. In total, data from 58 renal transplant recipients with 550 prospective 4βOHC measurements were included in the study. One sample per patient was collected before transplantation, and 2–12 samples per patient were collected 1–82 days after transplantation. The measured pretransplant 4βOHC concentrations ranged by >7-fold, with a median value of 22.8 ng/ml. Linear mixed-model analysis identified a 0.16-ng/ml increase in 4βOHC concentration per day after transplantation (P < 0.001), indicating a regain in CYP3A activity. Increasing estimated glomerular filtration rate after transplantation was associated with increasing 4βOHC concentration (P < 0.001), supporting that CYP3A activity increases with recovering uremia. In conclusion, this study indicates that CYP3A activity is regained subsequent to kidney transplantation. ER -