Single-dose and Steady-state Pharmacokinetics of Vancomycin in Critically Ill Patients Admitted to Medical Intensive Care Unit of India

RATIONALE: Vancomycin remains the standard of care for gram-positive bacterial infections, though there are significant developments in newer antibacterial agents. Efficacy can be improved by linking pharmacokinetic with pharmacodynamic principles, thus leading to optimum antibiotic exposure. There is scarcity of pharmacokinetic data in Indian intensive care unit (ICU) population. MATERIALS AND METHODS: Fifteen subjects with suspected or proven gram-positive bacterial infection of either gender between 18 years and 65 years of age were enrolled. Vancomycin at the dose of 1 g every 12 hours was administered over 1-hour period and pharmacokinetic assessments performed on blood samples collected on days 1 and 3. Vancomycin concentrations were measured on validated liquid chromatography mass spectrometry method. Pharmacokinetic parameters were calculated using Winnonlin (Version 6.3; Pharsight, St. Louis, MO). RESULTS: The mean C(max,) elimination half-life, AUC(0–12hours), volume of distribution, and clearance of single dose were 36.46 μg/mL (±14.87), 3.98 hours (±1.31), 113.51 μg/mL (±49.51), 52.01 L (±31.31), and 8.90 mL/minute (±3.29), respectively, and at steady state were 40.87 μg/mL (±19.29), 6.27 hours (±3.39), 147.94 μg/mL (±72.89), 56.39 L (±42.13), and 6.98 mL/minute (±4.48), respectively. The elimination half-life increased almost two-fold at steady state. The steady state mean AUC(0–24) was 295.89 µg/mL (±153.82). Out of 45 trough levels, 32 (71.11%) concentrations were below recommended range. CONCLUSION: Recommended AUC(0–24hours) and trough concentrations were not achieved in majority of patients with current dosing, suggesting reevaluation of current vancomycin dosing. Individualized treatment based on close monitoring of vancomycin serum concentrations in critically ill patients is imperative. HOW TO CITE THIS ARTICLE: Mali NB, Deshpande SP, Wandalkar PP, Gupta VA, Karnik ND, Gogtay NJ, et al. Single-dose and Steady-state Pharmacokinetics of Vancomycin in Critically Ill Patients Admitted to Medical Intensive Care Unit of India. IJCCM 2019;23(11):513–517.