Week 2 - Antibiotics

Question 1

What antibiotics affect cell wall synthesis?

Answer 1

Beta-lactams

glycopeptides

Question 2

What antibiotics affect cell membrane function?

Answer 2

Polymixins

Question 3

What antibiotics affect protein synthesis?

Answer 3

Tetracyclines
aminoglycosides
macrolides

Question 4

What antibiotics affect nucleic acid synthesis?

Answer 4

Quinolones

Question 5

What are the methods of resistance to antibiotics?

Answer 5

Drug inactivating enzymes (beta-lactamases, aminoglycoside enzymes)
altered target (target enzyme has lowered affinity for antibiotic)
altered uptake (decreased permeability or decreased efflux)

Question 6

What are the main groups of beta-lactams?

Answer 6

Penicillins, cephalosporins, carbapenems

Question 7

What are the main penicillins and what are they useful for?

Answer 7

Penicillin - mainly active against strep
Amoxicillin - active against strep and some activity against gram negatives
Flucoxacilin - active against staph and strep

Question 8

What can cephalosporins be used for?

Answer 8

Broad spectrum but no anaerobe activity

Question 9

What are carbapenems used for?

Answer 9

Very broad spectrum including anaerobes
active against most gram negatives
generally safe in penicillin allergies other than anaphylaxis

Question 10

What are the main types of glycopeptides?

Answer 10

Vancomycin, teicoplanin

Question 11

What can vancomycin be used for?

Answer 11

Active against most gram positives
some enterococci resistance
not absorbed
narrow therapeutic window

Question 12

What can teicoplanin be used for?

Answer 12

Similar to vancomycin but easier to administer

Question 13

What are the features of aminoglycosides?

Answer 13

Profound activity against gram negatives
good activity in blood/urine
narrow therapeutic window
generally reserved for severe gram negative sepsis

Question 14

What are trimethoprim and sulphonamides?

Answer 14

Inhibitors of folic acid synthesis
used alone for UTIs
when combined its used to treat PCP
has activity against MRSA

Question 15

What are the features of tetracyclins?

Answer 15

Broad spectrum but specific use in penicillin allergy usually for gram positives
oral only
active in atypical pathogens in pneumonia
active against chlamydia and some protozoa
not for children under 12

Question 16

What are macrolides used for?

Answer 16

Alternative to penicillin in mild gram positives

active against atypical respiratory pathogens

Question 17

What are quinolones used for?

Answer 17

Inhibit DNA gyrase

very active against gram negatives and atypical pathogens increasing resistance and risk of c difficile

Question 18

What are the main types of antifungal and what are they used for?

Answer 18

Azoles - active against yeasts and moulds, inhibit cell membrane synthesis.
Polyenes - inhibits cell membrane function

Question 19

What are the main types of antivirals and what are they used for?

Answer 19

Acilovir - when it phosphorylates it inhibits viral DNA polymerase, used for genital herpes, chickenpox and shingles. Oseltamivir - inhibits viral neuraminidase, used for influenza A and B