In this study we sought to evaluate the pharmacokinetics of colistin following intravenous (iv) administration of colistimethate sodium (CMS) in the critically ill neonates with Gram-negative bacterial infections. A single iv dose of CMS (approximately 150,000 IU/kg, equivalent to 5 mg/kg colistin base activity (CBA) was administered to 7 critically ill neonates. Mean (±SD) maximum plasma colistin concentration (Cmax) and area under the time-concentration curve from 0 to infinity (AUC0-∞) were 3.0 ± 0.7 µg/mL and 25.3 ± 10.4 µg.h/mL, respectively. Time to maximum concentration (Tmax), half-life (t1/2), apparent volume of distribution and clearance were 1.3 ± 0.9 h, 9.0 ± 6.5 h, 7.7 ± 9.3 L/kg, and 0.6 ± 0.3 L/h/kg, respectively.Following a dose regimen of 5 mg/kg CBA every 24 hours, the average concentration expected at steady-state (Cave,ss) is 1.1 ± 0.4 µg/mL. In critically ill neonates a single iv dose of 5 mg CBA/kg (approximately 150,000 IU/Kg of CMS) resulted in suboptimal plasma concentrations of colistin. According to our pharmacokinetics data, the dosage of CMS currently used in critically ill neonates is insufficient.
ASJC Scopus subject areas
- Pediatrics, Perinatology, and Child Health
- Infectious Diseases
- Microbiology (medical)