POST-ANTIBIOTIC EFFECT (PAE)

“It refers to persistent suppression of bacterial growth after limited exposure to an anti microbial agent.”

PAE In fact reflects the time required for bacteria to return to logarithmic growth. Most anti microbial have significant (PAE) in vitro (>1.5hrs) against susceptible Gram-positive cocci where as only a few antimicrobial (carbapenem, chloramphenicol, aminoglycosides, quinolones and Tetracyclines) possess post-antibiotic effect against susceptible Gram-negative bacilli.

In vivo PAE are usually much longer than in vitro. This is thought to be during PALE (Post Antibiotic Leukocyte Enhancement) and exposure of bacteria to sub inhibitory antibiotic concentration.

“PALE” (Post Antibiotic Leukocyte Enhancement) reflects the increased susceptibility of bacteria to phagocytic and bactericidal action of neutrophils”

The sub inhibitory drug concentration results in changed bacterial morphology and decreased rate of growth.