Serum concentrations of amoxicillin in neonates during continuous intravenous infusion

Area of Science:

• Neonatal pharmacology
• Infectious disease treatment
• Pharmacokinetics and pharmacodynamics

Background:

• Amoxicillin is a primary treatment for neonatal bacterial infections using intermittent dosing (ID).
• Increasing bacterial resistance and a lack of new antibiotics necessitate optimizing current therapies.
• Continuous infusion (CI) of beta-lactam antibiotics shows promise in adults, but CI guidelines for amoxicillin in neonates are lacking.

Purpose of the Study:

• To characterize the pharmacokinetics and pharmacodynamics of amoxicillin administered via continuous infusion (CI) during the initial three days of life.
• To identify an optimal dosing regimen for amoxicillin CI in neonates.
• To evaluate the safety and efficacy of amoxicillin CI in a neonatal population.

Main Methods:

• Study included neonates (gestational age > 34 weeks) at risk for infection requiring amoxicillin therapy.
• Serum amoxicillin concentrations were measured on days 1 and 3 of life during steady-state CI.
• Analysis of 22 serum samples from 11 patients.

Main Results:

• All neonates achieved and maintained therapeutic amoxicillin serum concentrations within the target range (Day 1: 55.4 mg/l; Day 3: 48.8 mg/l).
• Concentrations remained below toxic levels throughout the study period.
• No significant decline in amoxicillin concentration was observed between Day 1 and Day 3 (p=0.38).

Conclusions:

• Continuous infusion amoxicillin is safe and achieves therapeutic concentrations in neonates within the first three days of life.
• Further randomized controlled trials are warranted to compare the clinical efficacy of amoxicillin CI versus ID regimens.
• Optimizing amoxicillin dosing through CI may be a viable strategy to combat neonatal bacterial infections and emerging resistance.