Antibacterials Flashcards
how does Penicillin work ?
binds to DDtranspeptidase, a bacterial protein that is vital for making the outer cell wall of bacteria.
As a result of penicillin’s action, the cell wall is
weakened and the bacteria burst
name 2 penicillins
Amoxicillin, Flucloxacillin
Name 1 bacteria that Amoxicillin treats
Haemophilus Influenzae
Streptococcus pneumoniae
what type of Antibiotics target DNA synthesis?
Quinolones
Folic acid
antagonists
Name 1 Folic acid
antagonist ?
trimethoprim
sulphonamides
what type of Antibiotics target protein synthesis?
Aminoglycosides
Macrolides
Tetracyclines
Name 1 Aminoglycoside and 1 Macrolide
gentamicin
Erthromicin
what type of Antibiotics target cell wall synthesis?
Beta-lactams
Glycopeptides
Name 1 Glycopeptide and 1 Beta lactam
Vancomycin
Amoxcillin , Cefritaxone
why is Clavuronic acid used with Beta Lactams ?
it is a β-lactamase inhibitor. While not effective by itself as an antibiotic, when combined with penicillin-group antibiotics, it can overcome antibiotic resistance in bacteria that secrete β-lactamase,
What patients would you use prophylactic antibiotics?
Peri-operative
short term - Meningitis contact
Asplenia , immunodeficiency
how do you Measure antibiotic activity?
Disc testing
what is a MIC?
Minimum inhibitory concentrations
specific organism and antibacterial combination
what is time Dependant killing ?
for successful treatment there must be prolonger antibiotic at site of infection but not at high conc (fT>MIC) fraction of time concentration of unbound drug is greater than MIC
what is concentration dependant killing ?
Succesful treatment requires high antibiotic concentration at site of infection – But not for long [Cmax]/MIC ratio of maximum unbound drug concentration to MIC
which antibiotics require theraputic drug monitoring ?
Aminoglycosides - Gentamcin
• Vancomycin
what drug interactions does Macrolides have ?
clarithromycin inhibit CYP2D6 and CYP3A4 potentially
increasing plasma concentrations of co-prescribed drugs
- statins (esp. simvastatin)
- carbamazepine
what drug interactions does doxcycline have ?
Increased risk of bleeding when taken alongside warfarin -
monitor INR
• Potential increased hepatotoxicity when prescribed
alongside statins
Name the methods bacteria use to develop resistance
Alteration of target site
Alteration of metabolic pathways
Reduce IC antiobiotci accumulation
Antibiotic inactivation
what is MDR?
Non-susceptibility to at least one agent in three or more antimicrobial
categories
what is XDR?
extensively drug resistant
-Non-susceptibility to at least one agent in all but two or fewer
antimicrobial categories
what is PDR?
Pan drug resisitance
Non-susceptibility to all
agents in all antimicrobial
categories
