Mechanisms of Antibiotics

Question 1

What are the five mechanisms of antibiotics?

Answer 1

1. Inhibition of cell wall synthesis - most common
2. Inhibition of protein synthesis - 2nd most common
3. alteration of cell membranes
4. inhibition of nucleic acid synthesis
5. antimetabolite activity

Question 2

Which antibiotics cause inhibition of cell wall synthesis? (5)

Answer 2

1. Penicillin
2. Cephalosporin
3. monobactrams
4. carbapenems
5. Glycopeptides

Question 3

Which antibiotics cause inhibition of protein synthesis? (4)

Answer 3

1. Macrolides
2. Tetracyclines
3. Aminoglycosides
4. phenicols

Question 4

Which antibiotics cause inhibition of nucleic acid synthesis? (1)

Answer 4

Fluoroquinolones

Question 5

Which antibiotics cause folate pathway inhibition? (1)

Answer 5

Sulfomaides/trimethoprim

Question 6

Which antibiotics are bactericidal? (5)

Answer 6

1. Penicillin
2. Cephalosporin
3. Glycopeptides
4. fluorquinolones
5. aminoglycosides

Question 7

Which antibiotics are bacteristatic (2)

Answer 7

1. Macrolides

2. Tetracyclines

Question 8

Which antibiotics are bacterostatic on their own but when combined are bacteriocidal?

Answer 8

Sulfomaides/trimethoprim

Question 9

What is the beta-lactam antibiotic mechanism?

Answer 9

It acts as a D-Ala-D-Ala analog and prevents crosslinking in cell wall synthesis

Question 10

What are the four main classes of beta-lactam antibiotics?

Answer 10

1. Penicillin
2. cephalosporins
3. carbapenems
4. Monobactams

Question 11

is vancomycin active against gram - or gram +

Answer 11

ONLY active against gram +

Question 12

how does vancomycin work?

Answer 12

inhibit cell wall formation
(type of glycopeptide)
bacteriocidal

Question 13

how does fosfomycin work?

Answer 13

inhibit cell wall formation

Question 14

what is emperic therapy?

Answer 14

application of knowledge of the organisms most likely to cause infection given a clinical situation and its most likely susceptibility to an antibiotic

Question 15

what enzyme does antibiotics working against cell wall synthesis bind to?

Answer 15

transpeptidase

Question 16

What kind of antibiotic is aztreonam?

Answer 16

Monobactam - Beta lactam

Question 17

What kind of antibiotic is Vancomycin?

Answer 17

Glycopeptide - Cell wall inhitbitor

Question 18

What would you use to treat an intracellular infection?

Answer 18

Derivative of tetracycline

Question 19

What is the reason why aminoglycoside use needs to be monitored in a patient?

Answer 19

It can damage kidneys or cause hearing loss

Question 20

What type of antibiotic is erythromycin or azythromycin (Z pack)?

Answer 20

Macrolid - inhibitor of protein synthesis

Question 21

Which antibiotic would you use for an ESBL producer?

Answer 21

Carbapenam

Question 22

Do humans synthesisze folic acid?

Answer 22

No - this is why it is a good drug target for sulfonamides, trimethoprim and sulfamethoxazole

Question 23

What type of antibiotic is ciproflaxin?

Answer 23

A fluorquinolone - inhibitor of nucleic acid synthesis

Question 24

What type of antibiotic is rifampin?

Answer 24

Inhibitor of nucleic acid synthesis
Used in combo to treat
TB
MRSA

Question 25

What level of the MIC do you want to treat an infection with?

Answer 25

Four times the amount

Question 26

How long does it take for resistance to develop ?

Answer 26

72 hours