Purpose: The aim of this study was develop an optimal dosing regimen for netilmicin in neonates.
Methods: This was a population pharmacokinetic study in 97 neonates aged from 2 to 28 days after the due date who were being treated with netilmicin for suspected sepsis. The model was used to simulate dosing regimens.
Results: The principle factors influencing netilmicin clearance (CL) were postmenstrual age (PMA) and current body weight (CWT), and the principal determinant of volume of distribution (V) was CWT. The final covariate model was CL = 0.192 x (CWT/2)(1.35) x (PMA/40)(1.03), V = 1.5 x (CWT/2)(0.3). The optimal dosing was 5 mg/kg ever 36 h, 5 mg/kg every 24 h, 6 mg/kg every 24 h and 7 mg/kg every 24 h for neonates < or =27, 28-30, 31-33 and > or =34 weeks PMA, respectively.
Conclusion: Individualisation of netilmicin dosing in neonates requires adjustment of dose by body weight, and dosing interval by both PMA and CWT.