Antibiotics

Question 1

What does it mean when an antibiotic is antiseptic?

Answer 1

Kills and inhibits organisms on the body

Question 2

What is a disinfectant?

Answer 2

Kills and inhibits organisms on inanimate objects

Question 3

What is the definition of sterilization?

Answer 3

All organisms are killed

Question 4

What are the 2 MC antiseptics used in surgery?

Answer 4

Iodophors (Betadine) and chlorhexadine gluconate

Question 5

Betadine is good for what organism coverage?

Answer 5

GPCs and GNRs; poor for fungi

Question 6

Chlorhexadine is good for what organism coverage?

Answer 6

GPCs, GNRs, and fungi

Question 7

What classes of antibiotics are inhibitors of cell wall synthesis?

Answer 7

Penicillin, cephalosporins, carbapenems, monobactams, vancomycin

Question 8

What classes of antibiotics are inhibitors of 30s ribosome and protein synthesis?

Answer 8

Tetracycline, aminoglycosides (tobramycin, gentamicin), and linezolid

Question 9

What classes of antibiotics are inhibitors of the 50s ribosome and protein synthesis?

Answer 9

Erythromycin, clindamycin, Synercid

Question 10

What is the MOA of quinolones?

Answer 10

Inhibitor of DNA helicase (DNA gyrase)

Question 11

What is the MOA of rifampin?

Answer 11

Inhibitor of RNA polymerase

Question 12

What is the MOA of Flagyl (metronidazole)?

Answer 12

Produces oxygen radicals that break up DNA

Question 13

What is the MOA of sulfonamides?

Answer 13

PABA analogue which inhibits purine synthesis

Question 14

What is the MOA of trimethoprim?

Answer 14

Inhibits dehydrogenase reductase, which inhibits purine synthesis

Question 15

What class of antibiotics are bactericidal? Why?

Answer 15

Aminoglycosides. Bind irreversibly to ribosome

Question 16

What classes of antibiotics are bacteriostatic? Why?

Answer 16

Tetracyclines, clindamycin, erythromycin — all bind reversibly to ribosome

Question 17

What is the mechanism for resistance to penicillins?

Answer 17

Due to plasmids for beta-lactamase (staph aureus)

Question 18

What is the MC method of antibiotic resistance?

Answer 18

Transfer of plasmids

Question 19

What is the mechanism of resistance of MRSA?

Answer 19

Mutation in cell wall binding protein

Question 20

What is the mechanism of resistance in vancomycin resistant enterococcus (VRE)?

Answer 20

Mutation in cell wall binding protein

Question 21

What causes gentamicin resistance?

Answer 21

Due to modifying enzymes leading to a decrease in active transport of gentamicin into bacteria

Question 22

What is the appropriate peak levels of vancomycin?

Answer 22

20-40 ug/ml

Question 23

What is the appropriate trough level for vancomycin?

Answer 23

5-10 ug/ml

Question 24

What is the appropriate peak drug level of gentamicin?

Answer 24

6-10 ug/ml

Question 25

What is the appropriate trough for gentamicin?

Answer 25

<1 ug/ml

Question 26

What do you do if the peak level of a drug is too high?

Answer 26

Decrease the amount of each dose

Question 27

What do you do if the trough level of a drug is too high?

Answer 27

Decrease frequency of doses (increase time interval between doses)

Question 28

What organisms does penicillin cover?

Answer 28

Strep, syphilis, Neisseriea meningitides, Clostridium perfringens, beta-hemolytic strep, anthrax NOT EFFECTIVE AGAINST STAPH OR ENTEROCOCCUS

Question 29

What specific penicillin antibiotics cover staph?

Answer 29

Oxacillin, methicillin, and nafcillin -staph only

Question 30

What is the difference between ampicillin & amoxicillin and other penicillin antibiotics?

Answer 30

These 2 also cover enterococci

Question 31

What drugs make up unasyn?

Answer 31

Ampicillin and sulbactam

Question 32

What drugs make up Augmentin?

Answer 32

Amoxicillin and clavulanic acid

Question 33

What classes of organisms do Unasyn and Augmentin cover? Do not cover?

Answer 33

GPCs (staph and strep), GNRs, +/- anaerobic coverage Effective for enterococcus Not effective for pseudomonas, Acinetobacter, or serratia

Question 34

What is the MOA of sulbactam and clavulanic acid?

Answer 34

Beta-lactamase inhibitors

Question 35

What penicillins cover pseudomonas? What other bacteria do they cover?

Answer 35

Ticarcillin and piperacillin | GNRs-enterics, Acinetobacter, Serratia

Question 36

What are the side effects of ticarcillin and pipercillin?

Answer 36

Inhibits platelets and high salt load