Drug Dosing in Abnormal Kidney Function in Children

Abstract

As more than 60% of drugs are cleared by the kidneys, knowledge of drug handling and drug dosing in children with abnormal kidney function is essential. However, predicting drug clearance of drugs by the kidneys is not so straightforward. Very few drugs are actually cleared by glomerular filtration as this process requires that the drug to be unbound to plasma protein and an approprite size. Most drugs are actively transported into the lumen of the tubule and functionally, intact nephron endowment would be required for accurate drug clearance. Unfortunately, ways to assess nephron endowment are not clinically practical and therefore glomerular filtration rate (GFR) remains the best surrogate marker of nephron endowment. In this chapter we will discuss developmental changes of drug transport, how children handle drugs with normal and impaired kidney function, and general principles of drug dosing in children with chronic kidney disease (CKD). We will also cover drug dosing during renal replacement therapy.