Question

How do Polymyxins (topical) primarily exert their antibacterial effect?

A) Inhibition of DNA replication
B) Interference with cytoplasmic membrane function
C) Blocking protein synthesis
D) Disruption of cell wall synthesis

Answer 1

Polymyxins primarily exert their antibacterial effect by interfering with cytoplasmic membrane function.

Step-by-step explanation:

Polymyxins primarily exert their antibacterial effect by interfering with cytoplasmic membrane function. They have detergent-like properties and interact with the lipopolysaccharide component of the outer membrane of gram-negative bacteria, disrupting both their outer and inner membranes and ultimately killing the bacterial cells. Unfortunately, this membrane-targeting mechanism is not selective, so polymyxins can also target and damage the membrane of cells in the kidney and nervous system.