Antibiotics

Question 1

Name B-lactam antibiotics

Answer 1

Pencillins - penicillin, flucloxacillin, amoxicillin, piperacillin/tazobactam
Cephalosporins - ceftriaxone, ceftazidime, carbepenems

Question 2

How do B-lactam antibiotics work?

Answer 2

Stop crosslinking of peptidoglycan and cause autolysins to degrade cell wall (bactericidal)

Question 3

What is the coverage of B-lactams?

Answer 3

Gram positive

Some gram -ve

Question 4

Name glycopeptides

Answer 4

Vancomycin

Teicoplanin

Question 5

How do glycopeptides work?

Answer 5

Enter cell and bind to PG precursor molcule so they cannot be crosslinked - weak cell wall results in osmolysis (bactericidal)

Question 6

What is the coverage of glycopeptides?

Answer 6

Gram positive only

Question 7

Name macrolides

Answer 7

Erythromycin,azithromycin, clarythromycin

Question 8

How do macrolides work?

Answer 8

Pass through cell membrane and act on ribosomes to prevent peptide bonds being formed (bacteristatic)

Question 9

Name aminoglycosides

Answer 9

Gentamicin

Question 10

How do aminoglycosides work?

Answer 10

Bind to ribosome causing misreading of mRNA codon and insertion of wrong amino acid onto protein (bactericidal)

Question 11

What are aminoglycosides effective against?

Answer 11

Gram negative aerobic organisms

Question 12

What are macrolides used for?

Answer 12

Infections where bacteria ‘hide’ from immune system (legionella)
Bacteria without a proper cell wall (mycoplasma, chlamydia)

Question 13

Name tetracyclines

Answer 13

Doxycycline

Question 14

How do tetracyclines work?

Answer 14

Inhibit protein synthesis by binding to ribosomes (bacteristatic)

Question 15

What are tetracyclines used for?

Answer 15

Bacteria without a proper cell wall

Infections in penicillin-allergic patients

Question 16

How does metronidazole work?

Answer 16

Strand breakage of DNA (bactericidal)

Question 17

What does metronidazole cover?

Answer 17

True anaerobes - clostridium, bacteriodes

Question 18

How does trimethoprim work?

Answer 18

Inhibits bacterial folic acid synthesis

Question 19

What does trimethoprim cover?

Answer 19

Gram negatives and some gram positive

Question 20

Name fluoroquinolones

Answer 20

Ciprofloxacin, levofloxacin

Question 21

How do fluoroquinolones work?

Answer 21

Interact with topoisomerases responsible for DNA coiling (bactericidal)

Question 22

What is the coverage of fluoroquinolones?

Answer 22

Broad spectrum

Question 23

What are the 4 Cs? (Broad spectrum antibiotics)

Answer 23

Ciprofloxacin (and levofloxacin)
Cephalosporins (ceftriaxone, cefixime)
Co-amoxiclav
Clindamycin