Antibacterials

Question 1

how does Penicillin work ?

Answer 1

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

Question 2

name 2 penicillins

Answer 2

Amoxicillin, Flucloxacillin

Question 3

Name 1 bacteria that Amoxicillin treats

Answer 3

Haemophilus Influenzae

Streptococcus pneumoniae

Question 4

what type of Antibiotics target DNA synthesis?

Answer 4

Quinolones
Folic acid
antagonists

Question 5

Name 1 Folic acid

antagonist ?

Answer 5

trimethoprim

sulphonamides

Question 6

what type of Antibiotics target protein synthesis?

Answer 6

Aminoglycosides
Macrolides
Tetracyclines

Question 7

Name 1 Aminoglycoside and 1 Macrolide

Answer 7

gentamicin

Erthromicin

Question 8

what type of Antibiotics target cell wall synthesis?

Answer 8

Beta-lactams

Glycopeptides

Question 9

Name 1 Glycopeptide and 1 Beta lactam

Answer 9

Vancomycin

Amoxcillin , Cefritaxone

Question 10

why is Clavuronic acid used with Beta Lactams ?

Answer 10

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,

Question 11

What patients would you use prophylactic antibiotics?

Answer 11

Peri-operative
short term - Meningitis contact
Asplenia , immunodeficiency

Question 12

how do you Measure antibiotic activity?

Answer 12

Disc testing

Question 13

what is a MIC?

Answer 13

Minimum inhibitory concentrations

specific organism and antibacterial combination

Question 14

what is time Dependant killing ?

Answer 14

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

Question 15

what is concentration dependant killing ?

Answer 15

Succesful treatment
requires high
antibiotic
concentration at site
of infection
– But not for long
[Cmax]/MIC ratio of
maximum unbound
drug concentration to
MIC

Question 16

which antibiotics require theraputic drug monitoring ?

Answer 16

Aminoglycosides - Gentamcin

• Vancomycin

Question 17

what drug interactions does Macrolides have ?

Answer 17

clarithromycin inhibit CYP2D6 and CYP3A4 potentially
increasing plasma concentrations of co-prescribed drugs
- statins (esp. simvastatin)
- carbamazepine

Question 18

what drug interactions does doxcycline have ?

Answer 18

Increased risk of bleeding when taken alongside warfarin -
monitor INR
• Potential increased hepatotoxicity when prescribed
alongside statins

Question 19

Name the methods bacteria use to develop resistance

Answer 19

Alteration of target site
Alteration of metabolic pathways
Reduce IC antiobiotci accumulation
Antibiotic inactivation

Question 20

what is MDR?

Answer 20

Non-susceptibility to at least one agent in three or more antimicrobial
categories

Question 21

what is XDR?

Answer 21

extensively drug resistant
-Non-susceptibility to at least one agent in all but two or fewer
antimicrobial categories

Question 22

what is PDR?

Answer 22

Pan drug resisitance
Non-susceptibility to all
agents in all antimicrobial
categories