Low vancomycin trough concentration in neonates and young infants

Area of Science:

• Neonatal pharmacokinetics
• Pediatric infectious diseases
• Antimicrobial stewardship

Background:

• Vancomycin (VCM) is crucial for treating methicillin-resistant Staphylococcus aureus infections in infants.
• Optimizing initial VCM dosing in neonates is challenging, with existing regimens often yielding suboptimal trough concentrations.
• This study evaluated VCM trough concentrations in infants at our center using a specific pediatric regimen.

Purpose of the Study:

• To analyze initial vancomycin (VCM) trough concentrations in infants treated in the neonatal intensive care unit.
• To assess the efficacy of the Nelson's Pediatric Antimicrobial Therapy regimen in achieving target VCM levels.
• To identify factors influencing VCM trough concentrations in this population.

Main Methods:

• Retrospective analysis of 33 infants receiving VCM between July 2014 and June 2019.
• Categorization of patients based on initial VCM trough concentrations: <10 mg/L, 10-15 mg/L, and >15 mg/L.
• Monte Carlo simulation used to estimate VCM trough concentrations based on the Nelson regimen dosage.

Main Results:

• The majority of infants (24/33) had initial VCM trough concentrations below 10 mg/L.
• Only 4 patients had concentrations between 10-15 mg/L, and 5 had concentrations >15 mg/L.
• Simulation results showed a similar trend, with 26/33 patients having concentrations <10 mg/L.

Conclusions:

• The current Nelson regimen frequently results in subtarget initial vancomycin (VCM) trough concentrations in infants.
• No significant clinical characteristics were identified as predictors of VCM trough concentrations.
• Adjusting VCM dosage within the Nelson regimen, informed by simulation, is recommended to improve therapeutic efficacy.