Pregnancy:

• No data in human pregnancy.
• Limited data in animal models do not suggest teratogenicity.

Breastfeeding:

• Limited data indicate that colistin is minimally excreted into breastmilk following intramuscular administration of colistimethate.
• Because colistin is poorly absorbed orally, it is unlikely to be absorbed in appreciable amounts by the infant or adversely affect the breastfed infant.
• However, no studies have evaluated serum levels or adverse effects in breastfed infants whose mothers were receiving colistimethate.
• Breastfeeding is acceptable with the use of inhaled colistin or colistimethate.

Avoid in myasthenia gravis.

ALL DOSES FOR COLISTIN MUST BE EXPRESSED IN COLISTIN BASE. Colistin Base Activity (CBA) 1 mg is defined to be equivalent to colistimethate sodium (CMS) 30,000 units which is equivalent to ~2.4 mg CMS.

Attribution: Antimicrobial information adapted from BC Women's Hospital