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 (same as penicillins)

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

What is a risk of cephalosporin use and why?

Answer 16

Development of C. difficile

Cephalosporins are a broad-spectrum antibiotic

Question 17

Which antibiotics are glycopeptides?

Answer 17

Vancomycin

Teicoplanin

Question 18

Are glycopeptides bacteriostatic or bactericidal?

Answer 18

Bactericidal

Question 19

How does vancomycin prevent bacterial wall synthesis?

Answer 19

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

Question 20

In which form must glycopeptides be given?

Answer 20

IV - not absorbed orally

Question 21

How are glycopeptides excreted?

Answer 21

Kidneys

Question 22

Which kind of bacteria do glycopeptides have affect against?

Answer 22

Gram positive

NO anti gram negative activity

Question 23

When might vancomycin be given orally and why?

Answer 23

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

Question 24

Which groups of antibiotics affect protein synthesis?

Answer 24

Macrolides
Aminoglycosides
Tetracyclines
Also - chloramphenicol, clindamycin

Question 25

Are macrolides bacteriostatic or bactericidal?

Answer 25

Bacteriostatic

Question 26

Are aminoglycosides bacteriostatic or bactericidal?

Answer 26

Bactericidal

Question 27

How do macrolides affect bacterial protein synthesis?

Answer 27

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

Question 28

Which drugs are macrolides?

Answer 28

Erythromycin, clarithromycin, azithromycin

Question 29

How are macrolides excreted?

Answer 29

Via liver and biliary system | Not excreted in urine

Question 30

Which macrolide is safe in pregnancy?

Answer 30

Erythromycin

Question 31

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

Answer 31

They are lipophilic and cross cell membranes easily

Question 32

Which drug is an aminoglycoside?

Answer 32

Gentamicin

Question 33

Why must gentamicin be given intravenously?

Answer 33

It is not absorbed in the gut

Question 34

How does gentamicin inhibit bacterial protein synthesis?

Answer 34

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 35

Which bacteria does gentamicin primarily act against?

Answer 35

Gram negative aerobic organsims such as coliforms and pseudomonas aeruginosa

Question 36

When is gentamicin typically used in hospital?

Answer 36

In life threatening gram negative infection

Question 37

How is gentamicin excreted?

Answer 37

In the urine

Question 38

How are tetracyclines excreted?

Answer 38

Via the liver and biliary system

Question 39

How are chloramphenicol and clindamycin excreted?

Answer 39

Via the liver and biliary system

Question 40

Are tetracyclines bacteriostatic or bactericidal?

Answer 40

Bacteriostatic

Question 41

How does metronidazole work?

Answer 41

Causes strand breakage of bacterial DNA

Question 42

When is metronidazole used?

Answer 42

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

Question 43

What must bacteria produce to allow copy of it's own DNA?

Answer 43

Folic acid

Question 44

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

Answer 44

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

Question 45

How do fluoroquinolones act?

Answer 45

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

Question 46

Are fluoroquinolones bacteriostatic or bactericidal?

Answer 46

Bactericidal

Question 47

Which kind of antibiotic are fluoroquinolones?

Answer 47

Broad-spectrum

Question 48

Which antibiotics are broad-spectrum

Answer 48

Cephalosporins | Fluoroquinolones

Question 49

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

Answer 49

Fluoroquinolones

Question 50

How are fluoroquinolones excreted?

Answer 50

Urine

Question 51

What drugs are fluoroquinolones?

Answer 51

Ciprofloxacin | Levofloxacin

Question 52

What is the only use for levofloxacin?

Answer 52

Severe community acquired pneumonia in penicillin allergic patients

Question 53

What are some side effects of gentamicin?

Answer 53

Can cause kidney damage Dizziness Deafness

Question 54

What are some side effects of vancomycin?

Answer 54

"Red man syndrome" (allergy) | Kidney damage

Question 55

What is a side effect of the tetracyclines?

Answer 55

Permanent staining of teeth and bones

Question 56

Which antibiotic interacts with alcohol?

Answer 56

Metronidazole

Question 57

What are some side effects of fluoroquinolones?

Answer 57

Weakens tendons Joint problems Fits

Question 58

Which antibiotics are not to be given to pregnant women?

Answer 58

Gentamicin Tetracylcines Fluoroquinolones