AntimicrobialFDA Approved

Polymyxin B

Intravenous, Intrathecal, Topical

Overview

Polymyxin B is a cyclic lipopeptide antibiotic derived from Bacillus polymyxa, consisting of a heptapeptide ring and a tripeptide side chain acylated with a fatty acid tail. The molecule binds to lipopolysaccharide in the outer membrane of Gram-negative bacteria, causing membrane permeabilization and cell death.

Mechanism of Action

Its cationic residues interact electrostatically with anionic phosphate groups on lipid A. Polymyxin B is reserved for serious infections caused by multidrug-resistant Gram-negative pathogens when other options are unavailable..

Research Summary & Key Findings

Polymyxin B received FDA approval in the 1960s and remains in clinical use for severe infections caused by carbapenem-resistant Enterobacteriaceae and Acinetobacter species. Nephrotoxicity and neurotoxicity limit its use, prompting development of dosing protocols based on therapeutic drug monitoring. Recent pharmacokinetic studies have refined dosing strategies to optimize efficacy while minimizing adverse renal effects.

Clinical Status

FDA Approved

Polymyxin B has received FDA approval and is available for clinical use under appropriate medical supervision. Consult a qualified healthcare provider for prescribing information.

Administration Routes

IntravenousIntrathecalTopical

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Disclaimer: This information is provided for educational and research purposes only. It is not intended as medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider before starting any peptide therapy. The Peptide Association does not endorse or recommend any specific treatment protocol.