POLYMYXIN B

Description

Polymyxin B is a lipopeptide antibiotic isolated from Bacillus polymyxa. Its basic structure consists of a polycationic peptide ring and a tripeptide side chain with a fatty acid tail. Polymyxin B is a mixture of at least four closely related components, polymyxin B1 to B4, with polymyxin B1 and B2 being the two major components. Polymyxin B acts on Gram-negative bacteria by interacting with lipopolysaccharide (LPS) of the outer membrane and destabilizing it. Polymyxin B is indicated for the treatment of many bacterial diseases such as meningeal infections, urinary tract infections and bacteremia.

CNS Activity

Approval Year

Targets

Primary Target	Pharmacology	Potency
Myosin light chain kinase, smooth muscle 6	Inhibitor 8,297	70.0 µM [IC50]
Protein kinase C (Bos taurus) 2	Inhibitor 8,297	4.0 µM [IC50]
Na,K-ATPase (rat) 2	Inhibitor 8,297	800.0 µM [IC50]
Gram-negative-bacterium-type cell outer membrane assembly 2	Binding Agent 1,064

Conditions

Condition	Modality	Highest Phase	Product
Acute Infections due to Pseudomonas aeruginosa 2	Curative	Approved 8,429	POLYMYXIN B SULFATE
Meningeal infections due to H influenzae 2	Curative	Approved 8,429	POLYMYXIN B SULFATE
Urinary tract infections, E.coli 2	Curative	Approved 8,429	POLYMYXIN B SULFATE
Sepsis 71	Curative	Approved 8,429	POLYMYXIN B SULFATE

PubMed

Title	Date	PubMed
No data available in table

Patents

Sample Use Guides

In Vivo Use Guide

15,000 to 25,000 units/kg body weight/day

Route of Administration: Intravenous

In Vitro Use Guide

Polymyxin B MICs were determined for different strains of P. aeruginosa in Ca-MHB using a broth macrodilution method. The MIC was defined as the lowest concentration of drug that resulted in no visible growth after 24 h of incubation at 35°C in ambient air. The polymyxin B MIC ranged from 0.5 to 1 mg/liter.