10) Antimicrobrial Agents Flashcards
What are the major sites of action of antibiotics?
DNA synthesis
Protein synthesis
Cell wall synthesis
What are the primary therapeutic reasons for using antibiotics?
Prevention of infection (prophylaxis)
Treatment of significant bacterial infection
What considerations need to be made when choosing antibiotics?
Likely infectious agent
Efficacy
Safety (toxicity and interactions)
Admin route
What are some common adverse effects of antibiotics?
Allergic
Toxicity
Interactions
Impact on normal flora
What antibiotics are commonly monitored?
Aminoglycosides e.g. gentamicin
Vancomycin
What are the main genetic mechanisms of resistance?
Chromosomal gene mutation
Horizontal gene transfer
What are the main biochemical mechanisms of resistance?
Antibiotic inactivation e.g. beta-lactamase
Alteration of target site
Alteration of metabolic pathways
Reduced intracellular antibiotic concentration
How does resistance emerge in a bacterial population?
Local selection -> clonal dissemination -> global spread
Give some examples of antibiotic resistant bacteria:
MRSA
Glycopeptide resistant enterococci
Extensively drug resistant Klebsiella pneumoniae
How can resistance be prevented?
Antimicrobial stewardship
Infection control
What is time dependent killing?
Prolonged antibiotic presence at site of infection, not high concentration
What is concentration dependent killing?
High antibiotic concentration at site of infection but not for a prolonged period of time
