Association between vancomycin trough concentration monitoring and gestational age in neonates: a single-center, retrospective observational study

Abstract Background The vancomycin dosing regimen for neonates is primarily determined by gestational age (GA) and postnatal age(PNA). Nonetheless, initial trough concentrations frequently fall below therapeutic levels in neonates administered vancomycin. This study seeks to examine the relationship between vancomycin trough concentrations and gestational age in neonates, thereby offering a reference for individualized vancomycin dosing tailored to neonates of varying gestational ages. Methods A retrospective observational study was undertaken to collect clinical data on neonates treated with vancomycin and subjected to trough concentration monitoring in the Neonatal Intensive Care Unit (NICU) at Northwest Women’s and Children’s Hospital over the preceding six years. Results Utilizing a two-piecewise linear regression model, the P-value for the log-likelihood ratio was 0.007, indicating statistical significance, and an inflection point was identified at 34.6 weeks(approximately 242 days). For gestational ages less than 34.6 weeks, a positive correlation was observed between GA and the initial vancomycin trough concentration (TCV) (β = 0.08, 95% CI: 0.01, 0.14, p = 0.021). Conversely, for gestational ages exceeding 34.6 weeks, a negative trend of borderline significance (β = -0.10, 95% CI: -0.20 to 0.00, P = 0.059). Conclusion Vancomycin trough concentrations in neonates exhibit a significant correlation with GA. This retrospective study, conducted at a single center, revealed a non-linear relationship between gestational age and initial vancomycin trough concentrations in neonates, identifying an inflection point at approximately 34.6 weeks. The results indicate that existing gestational age-based dosing protocols may inadequately account for pharmacokinetic transitions, underscoring the necessity for prospective studies to validate therapeutic drug monitoring protocols stratified by gestational age.