Antibiotics

Question 1

How are most antibiotics cleared by the body?

Answer 1

renally excreted

Question 2

what are some drugs that are not handled by the kidney and thus metabolized by the liver?

Answer 2

clindamycin 
erythromycin
chloramphenicol 
metronidazole
nafcillin

Question 3

What is the MOA of penicillins?

Answer 3

cell wall synthesis inhibitors (bind to and inhibit PBP)

Question 4

what are some mechanisms of resistance to penicillin?

Answer 4

beta-lacatamase sensitive
alteration in the PBP site
changes in the cell mb (change in porin function)

Question 5

which type of penicillin is available only as an oral preparation?

Answer 5

penicillin V

Question 6

What drug interacts with penicillin and will increase serum concentrations of it?

Answer 6

probenecid

Question 7

What is the DOC for surgical prophylaxis?

Answer 7

Cefazolin (Ancef) 2g IV one hour before surgery

Question 8

What is the DOC for N. gonorrhea coverage?

Answer 8

Ceftriaxone (Rocephin)

250 mg IM injection

Question 9

What is the most active cephalosporin against P. aeruginosa?

Answer 9

Ceftazidime (Fortaz)

Question 10

Why is Imipenem always combined with Cilastatin?

Answer 10

Imipenem is destroyed in the kidney; Cilastatin inhibits renal enzymes from degrading the imipenem

Question 11

What does the Cockroft and Gault formula measure?

Answer 11

creatinine clearance

Question 12

What is the Cockroft and Gault formula?

Answer 12

creatinine clearance = (140-age) x (weight in kg)/ (serum Cr x 72)
*if women, multiply by 0.85

Question 13

you have to draw peaks & troughs when giving what type of antibiotics?

Answer 13

aminoglycosides

Question 14

which (peak or trough) is dose-dependent? which is time-dependent?

Answer 14

peak- is dose dependent

trough- is time dependent

Question 15

if peak is high and trough is normal, what would you do?

Answer 15

decrease the dose

Question 16

if peak is normal and trough is low, what would you do?

Answer 16

decrease the time between doses

Question 17

Which drugs are good against anaerobes?

Answer 17

Metronidazole (Flagyl)

Clindamycin (Cleocin)

Question 18

what AE is associated with vancomycin? how would you avoid this

Answer 18

Red Man syndrome- give it over 45-60 min to prevent

Question 19

What 3 aminoglycosides have indications for LE use?

Answer 19

gentamicin
tobramycin
amikacin

Question 20

Which aminoglycoside has the best activity against Serratia?

Answer 20

Gentamicin

Question 21

Which aminoglycoside is the most effective against P. aeruginosa?

Answer 21

tobramycin

Question 22

Which aminoglycoside is used for infection caused by Gram (-) organisms resistant to gentamicin and tobramycin?

Answer 22

amikacin

Question 23

what is the spectrum of activity of aminoglycisdes?

Answer 23

aerobic Gram (-) bacteria 
*is effective against staph and some strep but there are other drugs that are safer to use

Question 24

What are some of the feared side effects of aminoglycosides?

Answer 24

nephrotoxicity- reversible
otoxoticity- IRREVERSIBLE
neuromuscular blockade

Question 25

what is the spectrum of activity of Vancomycin?

Answer 25

Gram (+) bacteria only

Question 26

name some examples of Macrolides.

Answer 26

Erythromycin
Clarithromycin
Azithromycin

Question 27

What are the most frequently implicated organisms in cellulitis infections?

Answer 27

Staph aureus

Group A strep (Strep pyogenes)

Question 28

What are some oral alternatives used to treat cellulitis?

Answer 28

(empiric Gram + coverage)
Cephalosporin (Cephalexin)
Augmentin (amoxicillin/clavulanic acid)
Clindamycin

Question 29

What is tPA aka ?

Answer 29

alteplase

Question 30

What is the treatment for erythrasma?

Answer 30

oral erythromycin 1g/day