Polymyxins

Definition

Polymyxins are a class of antibiotics that target the cell membranes of Gram-negative bacteria. They are especially effective against multi-drug resistant strains.

5 Must Know Facts For Your Next Test

1. Polymyxins disrupt bacterial cell membranes by interacting with phospholipids, leading to cell death.
2. Colistin (polymyxin E) and polymyxin B are the most commonly used polymyxins in clinical settings.
3. They are often considered last-resort antibiotics due to their nephrotoxicity and neurotoxicity.
4. Polymyxins show poor absorption from the gastrointestinal tract, thus often administered intravenously or topically.
5. Resistance to polymyxins can arise through modifications of the lipid A component of lipopolysaccharides in bacterial membranes.

Related terms

Antibiotic Resistance:

The ability of bacteria to withstand the effects of an antibiotic.

Nephrotoxicity: Kidney damage caused by a toxin or drug.

Lipopolysaccharides:

Components found in the outer membrane of Gram-negative bacteria, crucial for maintaining membrane integrity and involved in antibiotic resistance mechanisms.