Mechanisms of Antibiotics Flashcards
What are the five mechanisms of antibiotics?
- Inhibition of cell wall synthesis - most common
- Inhibition of protein synthesis - 2nd most common
- alteration of cell membranes
- inhibition of nucleic acid synthesis
- antimetabolite activity
Which antibiotics cause inhibition of cell wall synthesis? (5)
- Penicillin
- Cephalosporin
- monobactrams
- carbapenems
- Glycopeptides
Which antibiotics cause inhibition of protein synthesis? (4)
- Macrolides
- Tetracyclines
- Aminoglycosides
- phenicols
Which antibiotics cause inhibition of nucleic acid synthesis? (1)
Fluoroquinolones
Which antibiotics cause folate pathway inhibition? (1)
Sulfomaides/trimethoprim
Which antibiotics are bactericidal? (5)
- Penicillin
- Cephalosporin
- Glycopeptides
- fluorquinolones
- aminoglycosides
Which antibiotics are bacteristatic (2)
- Macrolides
2. Tetracyclines
Which antibiotics are bacterostatic on their own but when combined are bacteriocidal?
Sulfomaides/trimethoprim
What is the beta-lactam antibiotic mechanism?
It acts as a D-Ala-D-Ala analog and prevents crosslinking in cell wall synthesis
What are the four main classes of beta-lactam antibiotics?
- Penicillin
- cephalosporins
- carbapenems
- Monobactams
is vancomycin active against gram - or gram +
ONLY active against gram +
how does vancomycin work?
inhibit cell wall formation
(type of glycopeptide)
bacteriocidal
how does fosfomycin work?
inhibit cell wall formation
what is emperic therapy?
application of knowledge of the organisms most likely to cause infection given a clinical situation and its most likely susceptibility to an antibiotic
what enzyme does antibiotics working against cell wall synthesis bind to?
transpeptidase
What kind of antibiotic is aztreonam?
Monobactam - Beta lactam
What kind of antibiotic is Vancomycin?
Glycopeptide - Cell wall inhitbitor
What would you use to treat an intracellular infection?
Derivative of tetracycline
What is the reason why aminoglycoside use needs to be monitored in a patient?
It can damage kidneys or cause hearing loss
What type of antibiotic is erythromycin or azythromycin (Z pack)?
Macrolid - inhibitor of protein synthesis
Which antibiotic would you use for an ESBL producer?
Carbapenam
Do humans synthesisze folic acid?
No - this is why it is a good drug target for sulfonamides, trimethoprim and sulfamethoxazole
What type of antibiotic is ciproflaxin?
A fluorquinolone - inhibitor of nucleic acid synthesis
What type of antibiotic is rifampin?
Inhibitor of nucleic acid synthesis
Used in combo to treat
TB
MRSA
What level of the MIC do you want to treat an infection with?
Four times the amount
How long does it take for resistance to develop ?
72 hours
