Colistin Sulfate (Polymyxin E)

Colistin is a polymyxin antibacterial. It is used intramuscularly or intravenously in the treatment of severe gram-negative infections, in cystic fibrosis by inhalation and orally for decontamination of the digestive tract in preparation for surgery. ^{(Coria 2011, Luque 2011)}

Its pharmacokinetic data (high volume of distribution and molecular weight) would explain the small passage into milk observed in two old publications after intramuscular administration. ^{(Borderon 1975 and Moiraghi 1964, cited in LactMed-colistimethate).}

The lack of oral bioavailability suggests little or no passage into infant plasma from ingested breast milk, except in premature infants and the immediate neonatal period, where there may be increased intestinal absorption.

Intravenous use authorised in Paediatrics and Neonatology.

Inhaled use is also compatible with breastfeeding. ^{(Middleton 2020)}