Innovative Use of Novel Biomarkers to Improve the Safety of Renally Eliminated and Nephrotoxic Medications

Over the last decade, the discovery of novel renal biomarkers and research on their use to improve medication effectiveness and safety has expanded considerably. Pharmacists are uniquely positioned to leverage this new technology for renal assessment to improve medication dosing and monitoring. Serum cystatin C is a relatively new, inexpensive, functional renal biomarker that responds more quickly to changing renal function than creatinine and is not meaningfully affected by age, sex, skeletal muscle mass, dietary intake, or deconditioning. Cystatin C has been proposed as an adjunct or alternative to creatinine for glomerular filtration rate assessment and estimation of drug clearance. Tissue inhibitor of metalloproteinase-2·insulin-like growth factor-binding protein 7 ([TIMP-2]·[IGFBP7]) is a composite of two damage biomarkers released into the urine at a checkpoint in mitosis when renal cells undergo stress or sense a future risk of damage. Concentrations of [TIMP-2]·[IGFBP7] increase before a rise in serum creatinine is evident, thus providing insightful information for evaluation in the context of other patient data to predict the risk for impending kidney injury. This article provides a brief overview of novel renal biomarkers being used as a mechanism to improve medication safety including a discussion of cystatin C, as part of drug-dosing algorithms and specifically for vancomycin dosing, and the use of [TIMP-2]·[IGFBP7] for risk prediction in acute kidney injury and drug-induced kidney disease. Select cases of clinical experience with novel renal biomarkers are outlined, and lessons learned and future applications are described.