Comparison of Vancomycin Pharmacokinetics Between Ischemic and Hemorrhagic Stroke.

PURPOSE: Acute stroke patients can demonstrate either augmented renal clearance (ARC) or acute/chronic kidney injury, affecting their clearance of vancomycin. This study assessed the pharmacokinetic parameters of vancomycin in stroke patients. METHODS: A single-center retrospective, observational, cohort study was conducted to assess pharmacokinetic parameters of vancomycin in stroke patients from June 2021 through June 2024. Evaluation of population pharmacokinetic parameters was completed using Lixoft Monolix Suite (2024R1). Analyses were performed comparing pharmacokinetic parameters among different stroke types and Augmented Renal Clearance in Trauma Intensive Care (ARCTIC) scores ≥6 vs. <6. RESULTS: There were 95 patients included in this study. Forty-six patients (48.4%) presented with acute ischemic stroke, 49 (51.6%) had hemorrhagic stroke. The total daily dose of vancomycin was 27.2 ± 7.8mg/kg/day. Between ischemic and hemorrhagic stroke, differences were seen in clearance (4.36L/hr vs. 5.30L/hr; p=0.018) and AUC0-24 (518.9µg/mL*hr vs. 454.5µg/mL*hr, p=0.038). Patients with an ARCTIC score ≥ 6 had a significantly higher elimination constant (0.105hr-1 vs. 0.070hr-1, p<0.001), shorter half-life (7.3hr vs. 12.1hr, p<0.001), smaller volume of distribution (0.63L/kg vs. 0.70L/kg, p=0.026), and faster systemic clearance (5.46L/hr vs. 4.10L/hr, p<0.001) than patients with an ARCTIC score <6. CONCLUSIONS: In this study, patients with the hemorrhagic stroke subtype had significantly higher clearance and lower AUC0-24 compared to ischemic stroke. While the mean AUC0-24 in both groups was within goal range, likely indicating individualized dosing practices, there was high variability in AUC0-24 in this stroke population. This study demonstrates the need for close TDM of vancomycin in the stroke population.