Population Pharmacokinetics of Amikacin in Neonates

Overview

Aminoglycosides such as Amikacin are routinely used in newborns for the treatment of neonatal sepsis due to gram-negative bacilli. Despite the frequency of this indication, it has not yet been possible to establish definitive dosage schedules that ensure effectiveness and low risk of toxicity, due to the high pharmacokinetic variability observed in this population. In addition to anthropometric variables, evidence from retrospective studies suggests that sepsis could be capable of significantly modifying the pharmacokinetics of aminoglycosides in neonates, but the investigators suggest conducting prospective studies of higher methodological quality to verify this hypothesis. Due to the lack of pharmacokinetic and pharmacodynamic (PK / PD) studies of Amikacin in this group of patients, the investigators have raised the need to develop a prospective observational study; describing a PK / PD model of amikacin in newborns with suspected sepsis.

Three blood samples will be taken from each of the 138 participants. As a standard of care, a sample will always be taken at 0.5h (Cmax) after the first dose and a sample before the second dose, which can be at 24h, 36h, or 48h as per physician indication. The third sample will be collected according to what has been assigned by a block randomization method, in one of the following moments: 1, 2, 4, 8, 12 or 18 hours after the administration of the first dose of Amikacin. The methods used to analyze the samples will be: Particle Enhanced Turbidimetric Immunoassay (PETIA), Architect C8000; and Homogeneous Microparticle Immunoassay in Solution (KIMS), Roche systems. The determination of the susceptibility and minimum Inhibitory Concentration (MIC) will be carried out by the laboratories of each hospital by agar dilution method. PK/PD profile of amikacin will be evaluated with NONMEM (non-linear mixed effects modelling) software for the analysis.

Conditions