2. antimicrobial therapy

Question 1

what are the classes of beta lactams

Answer 1

penicilin
cephalosporins
carbapenems

Question 2

what is the mechanism of action of beta lactams

Answer 2

(enzymatic) act on bacterial cell walls by binding to penicillin binding proteins (PBP) in the cell membrane which interferes with peptidoglycan synthesis

Question 3

what are macrolides used for

Answer 3

• penicillin allergy against gram positive staph and strep, e.g. skin and thread infections.
• atypical pneumonia

Question 4

examples of macrolides

Answer 4

erythromycin IV&PO
clarithromycin IV&PO (newer)
azithromycin PO (newer)

Question 5

what is the mechanism of action for erythromycin

Answer 5

bacteriostatic.

interferes with protein synthesis by ribosomal binding

Question 6

what are tetracyclines used for

Answer 6

• broad spectrum
• resp tract and soft tissue infections
• in penicillin allergy with side effects to macrolides
• atypical respiratory pathogens

Question 7

examples of tetracyclines

Answer 7

oxytetracycline
doxacycline
tigecycline

Question 8

what is tigecyline

Answer 8

recent tetracycline.
potent broad spectrum
works against gram positives, negatives and anaerobes

Question 9

mechanism of action of oxytetracycline + doxycycline

Answer 9

bacteriostatic.
inhibit tRNA binding to ribosome

doxy: PO, give once daily

Question 10

what is the mechanism of action of trimethoprim + co-trimoxazole

Answer 10

block bacterial nucleotide synthesis in the pathway of folic acid/nucleotide synthesis

Question 11

what do trimethoprim + co-trimoxazole work against

Answer 11

active against gram positive and negative bacteria

Question 12

what is a use of trimethoprim

Answer 12

commonly used against UTIs

Question 13

what is a use of co-trimexazole

Answer 13

(trimethoprim + sulfamethoxazole)

• treatment and prophylaxis of pneumocystis jirovecii pneumonia
• stenotrophomonas maltophilia infection
• nocardiosis

Question 14

examples of quinolones

Answer 14

ciprofloxacin
levofloxacin
moxifloxacin

Question 15

what is the mechanism and use of ciprofloxacin

Answer 15

• inhibit DNA gyrase (enzyme that supercoils bacterial DNA) = disrupt organism
• better action for gram positive

Question 16

what is the function of levo and moxifloxacin

Answer 16

new, have better gram positive cover

‘respiratory quinilones’

Question 17

what is the mechanism of aminoglycosides

Answer 17

interfere with ribosomal reading of mRNA

Question 18

what’s the function of aminoglycosides

Answer 18

gram positive mainly

• synergy with penicillin against strep
• mainly used IN SERIOUS SEPSIS
• potential for nerve 8 and renal toxicity: measure levels

Question 19

examples of aminoglycosides

Answer 19

gentamicin
amikacin
netilmicin
tobramycin

Question 20

what is the mechanism for glycopeptides

Answer 20

act on bacterial cell walls

Question 21

use of glycopeptides

Answer 21

against gram positive
treatment of MRSA
treatment of coagulase negative staph infection
occasionally when penicillin allergic

Question 22

examples of glycopeptides

Answer 22

vancomycin: potentially nephrotoxic

teicoplanin

Question 23

what is teicoplanin used for

Answer 23

outpatients with long lasting infections e.g. osteomyelitis

Question 24

metronidazole

Answer 24

breaks DNA strands.

active against all anaerobes, amoebae and trichomonad vaginalis

Question 25

linezolid

Answer 25

active against gram positive, including MRSA and glycopeptide-resistant enterococci

Question 26

chloramphenicol

Answer 26

occasional therapy of meningitis and topical treatment f eye infections. bone marrow toxicity

Question 27

fosfomycin

Answer 27

multi-resistant gram negative bacterial infections

Question 28

fidaxomycin

Answer 28

severe or recurrent c.difficile infections

Question 29

colistin

Answer 29

disrupts bacterial membrane. | reserved for multi- or pan-resistant gram negative infections

Question 30

daptomycin

Answer 30

a lipopeptide, similar activity to glycopeptide | against gram positive

Question 31

fusidic acid

Answer 31

staphylococcal infections only topical if systemic: use with second anti-staph agent

Question 32

rifampicin

Answer 32

v active against gram positive prosthetic valve endocarditis and other prosthetic infections. part of first line TB regimen

Question 33

what is the issue in terms of resistance about staphylococcus aureus

Answer 33

meticillin-resistant S. aureus (MRSA)

Question 34

what is the issue in terms of resistance about streptococcus pneumoniae

Answer 34

penicillin and multiply resistant

Question 35

what is the issue in terms of resistance about enterococcus faecium

Answer 35

glycopeptide and linezoid resistant

Question 36

what is the issue in terms of resistance about mycobactum tuberculosis

Answer 36

``` resistant to one or more anti-TB drugs: rifampicin isoniazid pyrazinamide ethambutol ```

Question 37

what is the issue in terms of resistance about salmonella typhi

Answer 37

multi-resistant in some parts of the world