title: Increase in tacrolimus trough levels after steroid withdrawal.
abstract: Although there are experimental reports of cytochrome P450 3A4 iso-enzyme (CYP3A4) induction by glucocorticoids, there are no clinical reports about an interaction between tacrolimus and steroids. Therefore, tacrolimus trough level and dose were compared after dose-normalization before and after withdrawal of prednisolone. After withdrawal of 5 mg prednisolone, the median tacrolimus dose-normalized level increased by 14% in the retrospective ( n=54), and by 11% in the prospective ( n=8) part of the study. After withdrawal of 10 mg, this increase was 33% ( n=30) and 36% ( n=14), respectively. An additional pharmacokinetic part of the study ( n=8) revealed an 18% increase in AUC ( P=0.05) after withdrawal of 5 mg prednisolone, which is compatible with a reduced metabolism after steroid withdrawal. The significant increase in tacrolimus exposure after steroid withdrawal may on the one hand counteract the reduction in immunosuppression intended by steroid withdrawal, and, on the other hand, may result in an increase of serum creatinine which could be misinterpreted as rejection.
authors.affiliation: Department of Internal Medicine, University Hospital of Maastricht, P.O. Box 5800, 6202 AZ, Maastricht, The Netherlands. evd@groupwise.azm.nl
authors.forename: Elly M
authors.initials: EM
authors.lastname: van Duijnhoven
authors.forename: Johannes M M
authors.initials: JM
authors.lastname: Boots
authors.forename: Maarten H L
authors.initials: MH
authors.lastname: Christiaans
authors.forename: Leo M L
authors.initials: LM
authors.lastname: Stolk
authors.forename: Nasrullah A
authors.initials: NA
authors.lastname: Undre
authors.forename: Johannes P
authors.initials: JP
authors.lastname: van Hooff
mesh_terms: D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D019540:Area Under Curve; D004347:Drug Interactions; D005190:Family; D006801:Humans; D007166:Immunosuppressive Agents / Q000097:blood / Q000493:pharmacokinetics / Q000627:therapeutic use; D016030:Kidney Transplantation / Q000276:immunology* / Q000502:physiology; D019520:Living Donors; D008657:Metabolic Clearance Rate; D009426:Netherlands; D011239:Prednisolone / Q000627:therapeutic use*; D012189:Retrospective Studies; D016559:Tacrolimus / Q000097:blood* / Q000493:pharmacokinetics / Q000627:therapeutic use; D044465:White People
chemical_list: D000305:Adrenal Cortex Hormones; D007166:Immunosuppressive Agents; D011239:Prednisolone; D016559:Tacrolimus