Drug which does not show "after-treatment" reaction: March 2011

Ans. B: INH A long PAE has been noted with fluoroquinolones, aminoglycosides and beta-lactam antibiotics Post antibiotic effect (PAE) It is defined as persistent suppression of bacterial growth after a brief exposure (1 or 2 h) of bacteria to an antibiotic even in the absence of host defense mechanisms. Factors that affect the duration of the post antibiotic effect include duration of antibiotic exposure, bacterial species, culture medium and class of antibiotic. It has been suggested that an alteration of DNA function is possibly responsible for post antibiotic effect following the observation that most inhibitors of protein and nucleic acid synthesis (listed below), induce long-term PAE against susceptible bacteria. Aminoglycosides, Fluoroquinolones, Tetracyclines, Clindamycin, Rifampicin and rifabutin Theoretically, the ability of an antibiotic to induce a PAE is an attractive propey of an antibiotic since antibiotic concentrations could fall below the MIC for the bacterium yet retain their effectiveness in their ability to suppress the growth