Anti-microbial agents

Question 1

give some examples of types of drugs that inhibit cell wall synthesis

Answer 1

B-lactams

Glycopeptides

Question 2

Give 3 types of B-lactams

Answer 2

Penicillins
Cephalosporins
Carbapenams

Question 3

give 2 examples of glycopeptides

Answer 3

Vancomcin

teicoplanin

Question 4

How are G+ and G- bacteria different

Answer 4

G+ = thick peptidoglycan wall
G- = thinner wall but covered in an outer memb - more resistant

Question 5

What is an issue with drugs that inhibit cell wall synth

Answer 5

only work when bac is growing/spreading - do not have effect on latent inf

Question 6

what B lactam does not get broken down by B lactamase

Answer 6

Flucloxicillin

Question 7

what makes up Co-Amox

Answer 7

Amoxicillin + clavulanic acid (B lactamase inhibitor) -> increases coverage

Question 8

give 2 examples of cephalosporins

Answer 8

ceftriaxone, cefuroxime

Question 9

what should be used against ESBL prod org

Answer 9

Carbapenams

Question 10

Give some features of B lactams

Answer 10

renally excreted - dec dose if impaired
do not cross BBB
short half life
broad spec

Question 11

what interactions should be considered with B alctams

Answer 11

penicillin has 10% cross reactivity with cephalosporins/carbapenms

Question 12

what type of bacteria are glycopeptides esp effective vs

Answer 12

G+ve - usefull vs MRSA and C. diff

Question 13

what antibiotic is esp effective vs pseudomonas aureginosa

name + class + method of action

Answer 13

gentamicin

Aminoglycoside - inhib prot synth

Question 14

how do aminoglycosides work

Answer 14

inhib prot synth - prev elongation of peptide chain and cause mRNA misreading

Question 15

what are the risks of using aminoglycosides

Answer 15

ototoxic and nephrotoxic - monitor levels

Question 16

how do tetracyclines work

Answer 16

inhib prot synth

bacteriostatic - prevent bac from reproducing

Question 17

what is a side effect of using tetracyclines

Answer 17

photosensitivity rash

Question 18

who should tetracyclines not be given to and why

Answer 18

deposit in growing bone - done give to kids/pregnant women

Question 19

give 2 examples of macrolides

Answer 19

erythromycin/clindamycin

Question 20

how do macrolides work

Answer 20

inhib prot synth by interfering with translocation

Question 21

what are macrolides esp effective against

Answer 21

campylobacter, legionella, pneumophilia

Question 22

what can be used to treat meningitis if a pt is penicillin allergic

Answer 22

chloramphenicol

Question 23

what are some important side effects of chrolamphenicol

Answer 23

risk of aplastic anaemia and grey baby syndrome

Question 24

what are oxazolidonides very active vs

Answer 24

MRSA (G+)

not active vs G-

Question 25

what are some side effects of oxazolidonides

Answer 25

thrombocytopenia and optic neuritis

Question 26

give 2 classes of drugs that work by inhibiting DNA synthesis

Answer 26

Quinolones

Nitroinidazoles

Question 27

how do quinolones work

Answer 27

act vs the alpha subunit of DNA gyrase to inhib DNA synth

Question 28

name a common nitroinidazole

Answer 28

metronidazole

Question 29

name a class and example of a drug that work by inhibiting RNA synth

Answer 29

rifamycins - rifampicin

bind to DNA-dependent RNA polymerase

Question 30

how can you easily check the compliance of rifampicin

Answer 30

will turn secretions orange

Question 31

give 2 classes of drugs that inhibit folate metabolism

Answer 31

sulphonmides

diaminopyrimidines

Question 32

what makes up co-trimazole

Answer 32

sulphamethoxalene + trimethoprim

Question 33

give a common diaminopyramidines and what it is used to treat

Answer 33

trimephoprim - used vs community acquired UTI

Question 34

what are the 4 ways that a bacteria gains resistance

Answer 34

1 - inactivation of AB/ enzyme chemical modulation

2. Reduced accumulation
3. Bypass Ab-sensitive step
4. Target modification

Question 35

what method of resistance fo ESBLs have

Answer 35

inactivation of Ab

Question 36

what mechanism of resistance does MRSA have vs flucloxicillin

Answer 36

target modification/ production of alternate target

encodes novel penicillin binding protein

Question 37

what is the mechanism of resistance for strep pneumonia vs penicillin

Answer 37

stepwise mut in PBP genes -> req inc concentrations of penicillins

Question 38

which bac are ESBLs most common in

Answer 38

klebsiella and E. Coli

Question 39

why would IV administration of an Ab be recommended over oral

Answer 39

if inf is serious/Deep/CNS

or if pt is not absorbing orally (eg sepsis -> drop in BP -> reduced perfusion of intestines)

Question 40

what are the types of antibiotics in terms of pharmacokinetics

Answer 40

T1 - Conc dendent killing - want C-max as high as possible
T2 - time dependent killing - maximize time above MIC
T3 - mix of 1 and 2 - maximize area under the curve that is over the MIC

Question 41

give an example of a c. dep killing antibiotic and how it should be given

Answer 41

aminoglycosides - given as big doses to maximize C-max

Question 42

give some examples of time dependent killing antibiotics and how the should be given

Answer 42

penicillin, cephalosporins, carbapenams

give frequently at lower doses

Question 43

give some examples of T3 antibiotics that are both concentration and time dependent killers

Answer 43

azithromycin
vancomycin
clindamycin