Session 12 Antibiotics Flashcards
What are the 5 main methods by which antimicrobials work?
- Inhibit cell wall synthesis
- Inhibit nucleic acid synthesis
- Stop metabolite production
- Inhibit cell membrane synthesis
- Inhibit protein synthesis
cell wall, nucleic acid, metabolites, cell membrane, protein = INHIBIT
Wall Acid Metabolite Membrane Protein = WAMMP
What does bactericidal mean?
destroying or killing bacteria
think suicidal
What does bacteriostatic mean?
stopping divisions and replication of bacteria, slowing the growth
bacteria are still alive and rely on body’s usual mechanisms
Which classes of antibiotic act on the cell wall?
are these static or cidal?
hint: there are 4 main ones
- Penicillin (amoxicillin, flucloxicillin)
- Ceflasporins (Ceftriaxone, Cephalexin)
- Glycopeptide (Vancomycin)
- Carbopenams (Meropenam)
these are all bactericidal
Which classes of antibiotic inhibit protein synthesis?
are these static or cidal?
hint: there are 3 main ones
- Macrolides (erythromycin, clarithromycin)
- Tetracycline (doxycycline)
- Aminoglycosides (gentamicin)
All are bacteriostatic but aminoglycosides are bactericidal as well!
Which class of antibiotic inhibits DNA / RNA synthesis?
bactericidal or static?
Quinolones
(ciprofloxacin, levofloxacin)
bactericidal or static = BOTH
Why do we need to perform drug monitoring?
some drugs may have a narrow therapeutic window
risk of toxicity / max effect of antibiotic
perform blood tests at specific times
Outline time dependent vs concentration dependent killing of bacteria
in time dependent:
* long half lives are beneficial - they spend longer at binding sites
in concentration dependent:
* levels are important - need a certain concentration at the binding sites
What are the three main reasons for using antibiotics?
- Short term management of bacterial infections
- Prophylaxis in acute settings (high risk procedures)
- Long term prophylaxis
What two things make up co-amoxiclav?
Clavulanic acid + Amoxicillin = co-amoxiclav
What is the MoA of clavulanic acid in co-amoxiclav?
inhibits effect of some beta lactamase enzymes so amoxicillin can work better
What is the MoA of amoxicillin in co-amoxiclav?
acts on cells walls of bacteria in usual standard MoA
What are the five I’s?
Re. Anti-microbial stewardship
“Have you I-fived?”
Identify Isolate Investigate Inform Initiate Treatment
In the Identify part of I-Five, what should you be focusing on? NB: think A-F
abroad blood born virus colonised diarrhoea (and vomiting) expectorating (cough) funny looking rash
A-F
What can you use to treat herpes simplex virus?
acyclovir
