Managing Dosage Adjustments in Pseudo-Hypocreatinemia: Insights from Vancomycin-Induced Nephrotoxicity in a Sarcopenic Patient.

Adjusting the dosage of renal excretory drugs according to the patient's renal function is essential. Vancomycin necessitates such adjustments due to its potential to cause nephrotoxicity when administered in excess. Creatinine-based equations for assessing the glomerular filtration rate, such as the Cockcroft-Gault and Modification of Diet in Renal Disease equations, are often used for dosage adjustments. However, vancomycin-induced nephrotoxicity sometimes occurs in critically ill patients, even in those with a normal estimated glomerular filtration rate. This case involved a 64-year-old male with cholangitis who developed vancomycin-induced nephrotoxicity. The patient was sarcopenic and had multiple risk factors that predisposed him to drug-induced nephrotoxicity. Moreover, creatinine-based equations may lead to the overestimation of glomerular filtration rate and subsequent vancomycin overdose. This case underscores the need for careful interpretation of creatinine-based assessments. We propose strategies to optimize medication dosing, particularly in patients with sarcopenia, to mitigate such risks.