PREDICTION OF NETILMICIN DISPOSITION IN NEONATES

Multiple regression analyses of data from 33 neonates who received netilmicin therapy showed that concurrent treatment with other drugs (Drg), creatinine clearance (CL(cr)), gestational age (GA), and an apgar score of less than 6 at 1 min (Agl') were significant determinants of netilmicin clearance. Apparent volume of distribution was significantly affected by postnatal age (PNA), gender, the presence of ascites and/or oedema (A/O), and whether or not the neonate was small for gestational age (SGA). The following formulae were obtained: CL (ml min-1 kg-1) = -0.108 - 0.210 (Drg) + 0.152(CL(cr)) + 0.019(GA) -0.128(Agl') (multiple R = 0.725, p < 0.001) V(d)(l kg-1) = 0.184 + 0.101(A/O) - 0.005(PNA) + 0.106(gender) + 0.057(SGA) (multiple R = 0.701, p < 0.001) The regression formulae were shown to predict netilmicin plasma concentrations with good precision and a non-significant bias in a further 15 neonates studied prospectively.