Skip to Content


Pronunciation: pol'e-mik'sin

Definition: A mixture of antibiotic substances obtained from cultures of Bacillus polymyxa (B. serosporus), an organism found in water and soils and obtainable as a crystalline hydrochloride; all are polypeptides containing various amino acids and a branched-chain fatty acid, usually (+)-6-methyloctanoic acid. There are several polymyxins, (designated A, B1, C, D, E, M, T), which are about equally effective against gram-negative bacteria, but which differ in toxicity, polymyxin E (colistin) and polymyxin B being the least toxic.

See Also: colistimethate sodium

Disclaimer: This site is designed to offer information for general educational purposes only. The health information furnished on this site and the interactive responses are not intended to be professional advice and are not intended to replace personal consultation with a qualified physician, pharmacist, or other healthcare professional. You must always seek the advice of a professional for questions related to a disease, disease symptoms, and appropriate therapeutic treatments.
© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.