Gentamicin Dosing in Neonates with Normal Renal Function: Trough and Peak Levels

Area of Science:

• Neonatal pharmacology
• Pediatric infectious diseases
• Antibiotic pharmacokinetics

Background:

• Gentamicin is a critical antibiotic for neonatal infections, necessitating careful therapeutic drug monitoring.
• Current dosing regimens may not consistently achieve target serum concentrations, impacting treatment efficacy and safety.

Purpose of the Study:

• To evaluate the effectiveness of a revised gentamicin dosing regimen in neonates.
• To determine the incidence of subtherapeutic peak and toxic trough gentamicin concentrations.
• To optimize gentamicin dosing for improved therapeutic outcomes in neonates.

Main Methods:

• A prospective cohort study involving neonates with normal renal function receiving gentamicin.
• Comparison of two gentamicin IV dosing regimens: 2.5 mg/kg vs. 3.5 mg/kg, with adjusted intervals based on gestational age.
• Assessment of serum gentamicin trough (≥ 2 mg/l) and peak (5-12 mg/l) concentrations.

Main Results:

• The initial 2.5 mg/kg regimen showed suboptimal peak concentrations in 23% of neonates < 30 weeks GA and 13% of those ≥ 30 weeks GA.
• The revised 3.5 mg/kg regimen achieved therapeutic peak concentrations in 98% of neonates.
• The 3.5 mg/kg regimen resulted in non-toxic trough concentrations in 86% of neonates.

Conclusions:

• The initial gentamicin regimen of 2.5 mg/kg was inadequate for achieving therapeutic peak levels in neonates.
• Increasing gentamicin dosage to 3.5 mg/kg significantly improved the achievement of therapeutic peak concentrations.
• The adjusted 3.5 mg/kg regimen demonstrated a favorable safety profile with predominantly non-toxic trough concentrations.