Dose Suggestions for Intravenous Colistin in Pediatric Patients: Caution Required

To the Editor—Mesini et al reported plasma concentrations of colistin in 7 pediatric patients (aged 46 days to 13 years) who were receiving intravenously the inactive prodrug colistimethate; across all patients, plasma colistin concentrations were measured on 13 occasions [1]. That report has been the subject of critical appraisal by Magréault et al [2], who expressed substantial concerns about the magnitude of the plasma colistin concentrations reported and the pharmacokinetic analysis conducted by Mesini and coworkers. I agree with Magréault et al and amplify their comments. I have very substantial concerns about the dosing recommendations implicitly presented in the report of Mesini and coworkers.