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.
Drug Class Combination–Associated Acute Kidney Injury
Objective: To evaluate the quality of available evidence of drug class combinations and their association with the development of acute kidney injury (AKI). Data Sources: A search of MEDLINE and Embase databases was completed using the following terms: “risk factor AND (acute kidney injury or acute kidney failure) AND (drug or medication).” Study Selection and Data Extraction: Inclusion criteria were the following: English language, full-text availability, and at least 1 drug-combination. Each citation was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) criteria. The literature was evaluated using the quality of evidence component of GRADE. No standardized definition of AKI was applied throughout.. Data Synthesis: Out of 2139 total citations, 151 were assessed for full-text review, with 121 citations (6%) meeting inclusion criteria, producing76 unique drug class combinations. Overall, 56 combinations (73.7%) were considered very low quality; 12 (15.8%) were considered low quality. There were 8 (10.5%) of moderate quality, and no combination was considered high quality. 58 (76%) combinations that had a single citation,with a mean of 1.6 citations per drug class combination. The combination of nonsteroidal anti-inflammatory drugs (NSAIDs) and diuretics was reported in 10 citations, the largest number of citations. Conclusions: Our study demonstrates a lack of well-designed studies addressing drug class combination–associated AKI. The combination of NSAIDs and diuretics with or without additional renin-angiotensin aldosterone agents had the strongest level of evidence. Despite limitations, the information included in this review may result in additional scrutiny about combining certain individual nephrotoxic drugs.