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Colistin sulfate: Full Drug Profile

Medically reviewed by Min Clinic Staff | Updated: January 2026

Colistin sulfate - General Information

Cyclic polypeptide antibiotic from Bacillus colistinus. It is composed of Polymyxins E1 and E2 (or Colistin sulfates A, B, and C) which act as detergents on cell membranes. Colistin sulfate is less toxic than Polymyxin B, but otherwise similar; the methanesulfonate is used orally.

 

Pharmacology of Colistin sulfate

Colistin sulfate is a polymyxin antibiotic agent. Polymyxins are cationic polypeptides that disrupt the bacterial cell membrane through a detergentlike mechanism. With the development of less toxic agents, such as extended-spectrum penicillins and cephalosporins, parenteral polymyxin use was largely abandoned, except for the treatment of multidrug-resistant pulmonary infections in patients with cystic fibrosis. More recently, however, the emergence of multidrug-resistant gram-negative bacteria, such as Pseudomonas aeruginosa and Acinetobacter baumannii, and the lack of new antimicrobial agents have led to the revived use of the polymyxins.

 

Additional information about Colistin sulfate

Colistin sulfate Indication

For the treatment of acute or chronic infections due to sensitive strains of certain gram-negative bacilli, particularly Pseudomonas aeruginosa.

Mechanism Of Action
Colistin sulfate is a surface active agent which penetrates into and disrupts the bacterial cell membrane. Colistin sulfate is polycationic and has both hydrophobic and lipophilic moieties. It interacts with the bacterial cytoplasmic membrane, changing its permeability. This effect is bactericidal. There is also evidence that polymyxins enter the cell and precipitate cytoplasmic components, primarily ribosomes.
Generic Name
Colistin
Drug Category
Anti-Bacterial Agents
Drug Type
Small Molecule; Approved
Other Brand Names containing Colistin
Colistin sulfate; Colistin sulfate, nonsterile; Colistin sulphate; Coly-mycin S; Polymyxin E sulfate; Polymyxin E. Sulfate;
Absorption
Very poor absorption from gastrointestinal tract.
Toxicity (Overdose)
Oral LD50 in rats is 5450 mg/kg. Overdosage with colistimethate can cause neuromuscular blockade characterized by paresthesia, lethargy, confusion, dizziness, ataxia, nystagmus, disorders of speech and apnea. Respiratory muscle paralysis may lead to apnea, respiratory arrest and death.
Half Life
5 hours
Dosage Forms of Colistin sulfate
Powder, for solution Intravenous
Chemical IUPAC Name
N-[(2S)-4-amino-1-[[(2S,3R)-1-[[(2S)-4-amino-1-oxo-1-[[(3S,6S,9S,12S,15R,18S,21S)-6,9,18-tris(2-aminoethyl)-3-(1-hydroxyethyl)-12,15-bis(2-methylpropyl)-2,5,8,11,14,17,20-heptaoxo-1,4,7,10,13,16,19-heptazacyclotricos-21-yl]amino]butan-2-yl]amino]-3-hydroxy-1-oxobutan-2-yl]amino]-1-oxobutan-2-yl]-5-methylheptanamide
Chemical Formula
C52H98N16O13
Organisms Affected
Gram-negative bacilli