Antibiotics module

Question 1

Which type of cell wall - gram positive or gram negative - contains large amounts of peptidoglycan?

Answer 1

Gram positive

Question 2

How do penicillins work?

Answer 2

Inhibit cell wall synthesis

Question 3

Are penicillins bacteriostatic or bactericidal?

Answer 3

Bactericidal

Question 4

How are penicillins excreted?

Answer 4

Via the kidneys

Question 5

Are penicillins safe in pregnancy?

Answer 5

Yes

Question 6

Which antibiotic contains a beta-lactam ring in the nucleus?

Answer 6

Penecillins

Cephalosporins

Question 7

Which bacteria is flucloxacillin useful for?

Answer 7

Staphylococci and streptococci only

Question 8

Which antibiotic is the drug of choice in staph aureus infection?

Answer 8

Flucloxacillin

Question 9

What is co-amoxiclav a combination of?

Answer 9

Amoxicillin and cluvulanic acid

Question 10

What is cluvulanic acid?

Answer 10

A beta-lactamase inhibitor - acts on the beta-lactamase produced by bacteria
It does not have antibiotic properties of its own

Question 11

Which antibiotics are cephalosporins?

Answer 11

Any antibiotic with “ceph” or “cef” in the name

Question 12

How do cephalosporins work?

Answer 12

Prevent cross-linking between peptidoglycans in bacterial cell wall. Bind to the penicillin binding protein

Question 13

Are cephalosporins bacteriostatic or bactericidal?

Answer 13

Bactericidal

Question 14

Where are cephalosporins secreted?

Answer 14

Kidneys

Question 15

Are cephalosporins safe in pregnancy?

Answer 15

Yes

Question 16

Which antibiotics are glycopeptides?

Answer 16

Vancomycin

Teicoplanin

Question 17

Are glycopeptides bacteriostatic or bactericidal?

Answer 17

Bactericidal

Question 18

How does vancomycin prevent bacterial wall synthesis?

Answer 18

Binds into the growing chain to prevent cross-linking between peptidoglycans

Question 19

In which form must glycopeptides be given?

Answer 19

IV - not absorbed orally

Question 20

How are glycopeptides excreted?

Answer 20

Kidneys

Question 21

Which kind of bacteria do glycopeptides have affect against?

Answer 21

Gram positive

NO anti gram negative activity

Question 22

When might vancomycin be given orally and why?

Answer 22

In C. difficile infection - is not absorbed by gut but acts topically on gut

Question 23

Are macrolides bacteriostatic or bactericidal?

Answer 23

Bacteriostatic

Question 24

Are aminoglycosides bacteriostatic or bactericidal?

Answer 24

Bactericidal

Question 25

How do macrolides affect bacterial protein synthesis?

Answer 25

Binds to ribosome between two aminoacyl-tRNA transferases to inhibit peptide bond formation between amino acids

Question 26

Which drugs are macrolides?

Answer 26

Erythromycin, clarithromycin, azithromycin

Question 27

How are macrolides excreted?

Answer 27

Via liver and biliary system | Not excreted in urine

Question 28

Which macrolide is safe in pregnancy?

Answer 28

Erythromycin

Question 29

Why are macrolides useful against bacteria which "hide" from host's immune system?

Answer 29

They are lipophilic and cross cell membranes easily

Question 30

Which drug is an aminoglycoside?

Answer 30

Gentamicin

Question 31

Why must gentamicin be given intravenously?

Answer 31

It is not absorbed in the gut

Question 32

How does gentamicin inhibit bacterial protein synthesis?

Answer 32

Binds to the 30S unit of the ribosome, causing misreading of the codons and coding for the synthesis of an incorrect protein This is fatal to the bacteria

Question 33

Which bacteria does gentamicin primarily act against?

Answer 33

Gram negative aerobic organsims such as coliforms and pseudomonas aeruginosa

Question 34

When is gentamicin typically used in hospital?

Answer 34

In life threatening gram negative infection

Question 35

How is gentamicin excreted?

Answer 35

In the urine

Question 36

How are tetracyclines excreted?

Answer 36

Lliver and biliary system | Urine (>60%)

Question 37

How are chloramphenicol and clindamycin excreted?

Answer 37

Via the liver and biliary system

Question 38

Are tetracyclines bacteriostatic or bactericidal?

Answer 38

Bacteriostatic

Question 39

How does metronidazole work?

Answer 39

Causes strand breakage of bacterial DNA (only in certain redox environments)

Question 40

When is metronidazole used?

Answer 40

Infection from "true anaerobes" | Some infections caused from protozoa

Question 41

How do sulphamethoxazole and trimethoprim work to inhibit bacterial DNA replication?

Answer 41

Inhibit enzymes which bacteria use to form folic acid for DNA replication

Question 42

How do fluoroquinolones act?

Answer 42

Interact with topoisomerases - enzymes responsible for the coiling and uncoiling of bacterial DNA This stops DNA from replicating

Question 43

Are fluoroquinolones bacteriostatic or bactericidal?

Answer 43

Bactericidal

Question 44

Which antibiotics are broad-spectrum

Answer 44

Cephalosporins | Fluoroquinolones

Question 45

Which is the only antibiotic that can be given orally to treat pseudomonas infection?

Answer 45

Ciplrofloxacin

Question 46

How are fluoroquinolones excreted?

Answer 46

Urine

Question 47

What drugs are fluoroquinolones?

Answer 47

Ciprofloxacin, moxifloxacin, | Levofloxacin

Question 48

What are some side effects of gentamicin?

Answer 48

Can cause kidney damage Dizziness Deafness

Question 49

What are some side effects of vancomycin?

Answer 49

"Red man syndrome" (allergy) | Kidney damage

Question 50

What is a side effect of the tetracyclines?

Answer 50

Permanent staining of teeth and bones

Question 51

Which antibiotic interacts with alcohol?

Answer 51

Metronidazole

Question 52

What are some side effects of fluoroquinolones?

Answer 52

Weakens tendons Joint problems Fits

Question 53

Which antibiotics are not to be given to pregnant women?

Answer 53

Gentamicin Tetracylcines Fluoroquinolones