Mechanisms of Action of Antibiotics Flashcards
Name the three methods of antibiotic action
- Inhibition of cell wall synthesis
- Inhibition of protein synthesis
- Inhibition of nucleic acid synthesis
Name the two types of drugs involved in inhibition of bacterial cell wall synthesis
Beta-Lactams and Glycopeptides
Give two examples of Beta-Lactams
Penicillins and Cephalosporins
How does interruption of cell wall synthesis lead to bactericidal action?
Damaged cell walls cause autolytic cells to destroy the bacteria
Give two examples of glycopeptides
Vancomycin and teicoplanin
Glycopeptides only act on what kind of bacteria?
Gram positive
Glycopeptides are not absorbed in the GI tract - how are they administered?
Paraenterally
What is a common problem with vancomycin?
Toxicity
What are the side effects of vancomycin?
Otoxicity, Nephrotoxicity and skin rashes
Describe the relative toxicity of teicopanin
Less toxic
Name the four groups of antibiotics that target protein synthesis
Macrolides and tetracyclines, oxazolidinones, aminoglycosides, cyclic lipopeptides
Give an example of an aminoglycoside
Gentamicin
Gentamicin is used to treat what type of bacteria?
Gram negatives
How is gentamicin administered?
Injectable, not oral
Describe the action of gentamicin on staphs. and streps.
Most Staph. spp are susceptible but not Strep. spp
Give a sound example of a cyclic lipopeptide
Daptomycin
When is daptomycin used?
Used against serious MRSA cases on specialist advice
Give an example of an oxazolidinone
Linezoid
Linezoid has good activity against what infection?
MRSA
Give examples of macrolides and tetracyclines
Erythromycin, clarithromycin and tetracycline
When are macrolides used?
As alternatives to penicillin (gram positive infections)
What infections show significant resistance to macrolides and tetracyclines?
Staph. aureus, pyogenes and Strep. pneumoniae
What drug groups of antibiotics that inhibit nucleic acid synthesis?
Trimethoprim and sulphamethoxazole and fluoroquinolones
Given an example of a fluoroquinolone
Cirpfloxacin
Cirpfloxacin is useful against what type of bacteria?
Gram negative
Why cannot cirpfloxacin be used in children?
Interferes with cartilage formation
Trimethoprim is used on its own to treat what pathology?
UTI
