What Do We Know About Steroids Metabolism and ‘PK/PD Approach’ in AKI and CKD Especially While on RRT – Current Status in 2014

The knowledge on PK behavior of steroid drugs such as prednisolone or prednisone has indeed been expanding but at a rather slow pace. First, convenient, rapid, and specific determination of plasma levels of these steroids was largely indebted to the breakthrough of high performance liquid chromatography (HPLC). Second, prednisolone is non-linearly protein-bound. Since unbound prednisolone is the biologically active compound, only the measurement of this free fraction in plasma is relevant. Third, the short half-life of prednisolone precludes to reach steady-state levels and requires determination of the area under the concentrationtime curve. Fourth, prednisolone and prednisone are mutually convertible. Intravenous prednisolone, however, is administered as a pro-drug ester, which renders comparison Published online: November 29, 2014 Prof. Patrick M. Honoré, MD, PhD, FCCM ICU Department, University Hospital Brussels Vrije Universiteit Brussel – VUB University Laarbeeklaan 101, BE–1090 Brussels (Belgium) E-Mail Patrick.Honore @ uzbrussel.be © 2014 S. Karger AG, Basel 0253–5068/14/0382–0154$39.50/0