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September 23, 1961


Author Affiliations


From the Department of Medicine, University School of Medicine.

JAMA. 1961;177(12):854. doi:10.1001/jama.1961.73040380019005a

THE SEARCH for agents with which to treat Pseudomonas infections has resulted in the discovery of colistin (Colymycin), a new polypeptide antibiotic which has recently become available for intramuscular use as colistimethate sodium. Colistin was isolated in Japan and is similar to, but not identical with, any of the known polymyxins. It has been the subject of over 100 reports in the foreign literature, and 20 articles in this country since 1958. The majority of these reports contain data indicating that colistin may have distinct advantages over the polymyxins because of its wider therapeutic index. In one study of acute toxicity in animals, the LD50 dose of parenterally administered colistin was 2.3 (s.c.) to 41 (i.v.) times that of similarly administered doses of polymyxin B.1

In vitro, colistin shows bacteriostatic and bactericidal activity against a variety of gram-negative organisms, and against Pseudomonas aeruginosa in particular. Approximately 80