Antibiotics

Question 1

How do beta-lactams work?

Answer 1

inhibits cell wall synthesis or repair by binding to penicillin binding proteins

Question 2

what type of antibiotic is penicillin

Answer 2

beta-lactam

Question 3

what type of antibiotic is cephalosporin

Answer 3

beta-lactam

Question 4

what type of antibiotic is carbapenems

Answer 4

beta-lactam

Question 5

how do glycopeptides work?

Answer 5

inhibits peptidoglycan synthesis by binding to precursors

Question 6

what type of antibiotic is vancomycin?

Answer 6

glycopeptide

Question 7

how does tetracyclin work?

Answer 7

inhibits protein synthesis (more specifically, it prevents attachment of tRNA to mRNA)

Question 8

how do macrolides work?

Answer 8

inhibits protein synthesis (specifically peptide elongation)

Question 9

how does choramphenicol work?

Answer 9

inhibits protein synthesis (specifically peptide elongation)

Question 10

how does clindamycin work?

Answer 10

inhibits protein synthesis (specifically peptide elongation)

Question 11

how does nitrofurantoin work?

Answer 11

inhibits protein synthesis (non-specific binding)

Question 12

how does linezoid work?

Answer 12

inhibits protein synthesis (specifically tRNA attachment to mRNA)

Question 13

how do aminoglycosides work?

Answer 13

inhibits protein synthesis (specifically ribosome interaction with mRNA)

Question 14

how does ciprofloxacin work?

Answer 14

binds topoisomerase

Question 15

how does rifamycin work?

Answer 15

binds DNA-dependent RNA polymerase

Question 16

how does metronidazole work?

Answer 16

bacterial nitroreductase alters this drug into a metabolite that disrupts bacterial DNA

Question 17

how does daptomycin work?

Answer 17

binds inner cell membrane and ruptures it

Question 18

how do polymyxins works?

Answer 18

interacts with LPS in outer membrane and ruptures it

Question 19

how do sulfonamides work?

Answer 19

compete with PABA to block folic acid formation

Question 20

how does trimethoprim work?

Answer 20

inhibits dihydrofolate reductase to block folic acid synthesis

Question 21

which bacteria are resistant to rifamycin?

Answer 21

gram negative (bc rifamycin cannot cross outer membrane)

Question 22

which bacteria are resistant to daptomycin?

Answer 22

gram negative (bc daptomycin cannot cross outer membrane)

Question 23

which bacteria are resistant to polymyxins?

Answer 23

gram positive (bc it works to destroy outer membrane)

Question 24

what type of peptide is daptomycin?

Answer 24

lipopeptide

Question 25

what type of peptide are polymycins?

Answer 25

polypeptide

Question 26

which 3 antibiotics are susceptible to beta-lactamases?

Answer 26

penicillin, cephalosporin, carbapenems

Question 27

name 3 beta-lactamase inhibitors

Answer 27

clavulinic acid, subactam, tazobactam (combined with penicillin)

Question 28

4th generation beta-lactams are effective against what?

Answer 28

most enterobacteriacea | pseudomonas aeruginosa

Question 29

why are 4th generation beta-lactams preferred to 3rd generation?

Answer 29

they are stable against bacterial beta-lactamase

Question 30

Vancomycin is only effective against what type of bacteria and why?

Answer 30

gram positive. because they interfere with peptidoglycan synthesis which is not abundant in gram negative

Question 31

what is an example of a 4th generation beta-lactam

Answer 31

Cefepime

Question 32

name 5 broad spectrum antibiotics that inhibit protein synthesis

Answer 32

tetracyclin, macrolides, choramphenicol, clindamycin, nitrofurantoin

Question 33

what is a narrow spectrum antibiotic that inhibits protein synthesis of gram negative organisms?

Answer 33

aminoglycosides

Question 34

what are two narrow spectrum antibiotics that inhibits protein synthesis of gram positive organsims?

Answer 34

streptogramins | linezoid

Question 35

name an antibiotic that is an example of a quinolone

Answer 35

ciprofloxacin (a quinolone)

Question 36

name an antibiotic that is an example of a rifamycin

Answer 36

rifampin

Question 37

what are the physical characteristics of quinolones?

Answer 37

small hydrophilic molecule that crosses outer membrane easily

Question 38

what is a side effect of polymyxins?

Answer 38

nephrotoxic

Question 39

what test provides susceptibility information for antibiotics? how does it work

Answer 39

Kirby-bauer- discs w. different drugs--> measure zone of inhibition

Question 40

what 3 tests provide MIC and MBC information for antibiotics? how do they work

Answer 40

1. ) broth dilution- use microwells--> add varying concentrations of antibiotics 2. ) epsilometer test- get strip with gradient of antibiotic concentration and look for areas of bacterial growth 3. ) automated instrument system- is a machine that detects changes in bacterial growth

Question 41

name the 6 bacteria that are becoming resistant to antibiotics

Answer 41

- enterococcus faecium: vancomycin - staph aureus: methicillin - klebsiella- 4th gen beta-lactams (produce carbapenemas) - acinetobacter baumanii: MDR - pseudomonas aeruginosa: MDR - enterobacter species: Amp C?

Question 42

what are concentration dependent antibiotics? how do they bind? are they bacteriostatic or bacteriocidal?

Answer 42

- reversibly bind to target - their action is dependent on peak concentration of antibiotic - usually bacteriostatic & inhibit replication (don't kill organism)

Question 43

what are time-dependent antibiotics? how do they bind? are they bacteriostatic or bacteriocidal?

Answer 43

- irreversibly bind to target - their action is dependent on antibiotic concentration over a certain amount of time - associated with a more intermittent dosing schedule - usually bacteriocidal & destroys cell wall, membrane, DNA - usually requires greater MIC?

Question 44

name 4 classes of antibiotics that are concentration dependent. what is the PK/PD measurement?

Answer 44

-aminoglycosides -daptomycin? -qunilones -metronidazole (24 hr AUC/MIC)

Question 45

name 4 classes of antibiotics that are time-dependent. what is the PK/PD measurement?

Answer 45

-penicillins -cephalosporins -carbapenems -monobactams (time above MIC)

Question 46

name 7 time dependent classes of antibiotics that have a persistent effect. what is the PK/PD measurement?

Answer 46

- clindamycin - linezolid - tetracylins - vancomycins - erythromycin - azithromycin - clarithromycin (24 hr AUC/MIC)