Vanco PK

Question 1

what is the MoA of vanco?

Answer 1

binds to peptidoglycan on bacterial cell membrane and interferes with cell wall building/repair

Question 2

what does vanco treat?

Answer 2

MRSA, MSSA, and coagulase-negative staph

Question 3

Vanco should be discontinued after 72 hours if?

Answer 3

MRSA not found

Question 4

what is the minimum inhibitory concentration for vanco?

Answer 4

1 mg/L or less

Question 5

what’s the bioavailability of vanco when given IV/IM?

Answer 5

F=1

Question 6

what’s the bioavailability of vanco given intraperitoneally?

Answer 6

F= 0.5-0.6

Question 7

what’s the dose for vanco given intrathecal/intraventricular?

Answer 7

5-20mg q24h

Question 8

does vanco cross placenta?
does it get into breast milk?

Answer 8

yes and yes

Question 9

when do we draw a vanco peak concentration after administration? what about post-distribution?

Answer 9

after 4-5 alpha half-lives
draw 1 hour after a 1 hour infusion

Question 10

what is vancos half-life?
time to steady-state?

Answer 10

8 hours
48 hours

Question 11

what are our monitoring parameters for efficacy and toxicity for vanco?

Answer 11

efficacy:
vitals (temp)
WBCs
repeat culture and sensitivty (C&S)

toxicity:
kidney function
SCr
Urine I/O
hearing & balance
vanco trough

Question 12

what is the target vanco AUC for MIC =1 mg/L?

Answer 12

400-600 mg/L*h

Question 13

why do we prolong infusion time w/ vanco doses over 1000mg?

Answer 13

prevent vanco flushing syndrome

Question 14

some morbidly obese pts require every __ hour dosing

Answer 14

8

Question 15

which of the following is true regarding vancomycin and obesity?
A. VD is moderately increased
B. T1/2 decreases to about 6 hours
C. Clearance increases
D. The Dosing interval remains the same

Answer 15

C

Question 16

for burn patients, may need every ______ hour vanco dosing

Answer 16

6-8

Question 17

a central line vanco concentration should NOT be _________

Answer 17

> 10 mg/mL

Question 18

a peripheral line vanco concentration should NOT be __________

Answer 18

> 5 mg/mL

Question 19

when do we consider using a loading dose for vanco?

Answer 19

seriously ill pts:
Severe sepsis
meningitis
bacteremia
infective endocarditis
pneumonia
osteomyelitis

Question 20

what is vanco loading dose?

Answer 20

25-30 mg/kg based on actual body weight (max 3g)

Question 21

what is the cockcroft-gault equation?

Answer 21

CLCR= [(140-age) x IBW / 72 X SCr] x 0.85 (for females)

Question 22

how do we calculate IBW?

Answer 22

Men: 50 kg + 2.3 * (inches over 5 ft)
Women: 45.4 kg + 2.3 * (inches over 5 ft)

Question 23

how do we determine what weight to use to calculate creatinine clearance?

Answer 23

use total body weight if its less than IBW. if IBW is 120% or more over TBW, use ABW

Question 24

how do we calculate ABW?

Answer 24

IBW + [0.4 (TBW-IBW)]

Question 25

when do we use a minimum Scr =1?

Answer 25

for age 65 or more or malnourished pts with Scr less than 1

Question 26

how do we initially dose vanco based on creatinine clearance?

Answer 26

>80: 15 mg/kg q8-12h 50-80: 15 mg/kg q12h 30-50: 15 mg/kg q24h <15: 15 mg/kg as one time dose ** not to exceed 2g q8h recommended only in patients under 40 and CLCR over 80

Question 27

all vanco troughs should be drawn __________ to next dose (within ______ minutes of next dose)

Answer 27

immediately prior, 30

Question 28

vanco troughs should be obtained at steady-state before ___________ dose in patient with stable kidney function or before _________ dose in patients requiring >24 hour dosing such as CKD patients

Answer 28

4th or 5th 2nd or 3rd

Question 29

volume of distribution for vanco is determined using the equation: when do you use ABW?

Answer 29

0.7 or 0.8 L/kg * weight if >120% IBW

Question 30

mcg/ml = mg/L

Question 31

what does t' mean?

Answer 31

infusion time: t'=2 if vanco was infused over 2 hours

Question 32

what does tau mean?

Answer 32

the dosing interval: q12h, q24h...

Question 33

if you want to change the Cmax, you should? if you want to change the Cmin, you should?

Answer 33

change the dose change the dosing interval

Question 34

is vanco concentration-dependent or time-dependent killing?

Answer 34

time-dependent

Question 35

AUC divided by the MIC is the primary predictive pharmacodynamic parameter for _____

Answer 35

efficacy

Question 36

T/F AUC is the measure of cumulative drug exposure

Answer 36

true

Question 37

T/F AUC is the serum concentration-time curve over a dosing interval

Answer 37

true

Question 38

vanco trough range should be?

Answer 38

10-20 mg/L

Question 39

for calculating extrapolated Cmax, Tmax is the time between __ and the _______

Answer 39

T1, end of infusion

Question 40

Ct = concentration at the start of infusion which is the same as?

Answer 40

trough (Cmin) at steady-state

Question 41

back extrapolating to the end of the infusion will a. overpredict AUC b. underpredict AUC c. predict AUC exactly

Answer 41

b

Question 42

what is the AUC associated w/ AKI?

Answer 42

600-800 mg/L*h

Question 43

what is the AUC associated w/ nephrotoxicity?

Answer 43

700-1300 mg/L*h

Question 44

smaller volume of distribution = what to k and half-life?

Answer 44

faster elimination and shorter half-life

Question 45

prior to systemic circulation, oral drugs metabolized by cyp are located in the: a. small intestine b. liver c. small intestine and liver d. small intestine, liver, kidney, and other minor organs

Answer 45

d

Question 46

which dosage form(s) have a high first-pass effect? a. IV/IM b. SL c. capsule/tablet d. transmucosal e. transdermal f. suppository g. inhalation

Answer 46

c

Question 47

in general, if a drug has a high first-pass effect, then switching from IV to oral dose requires: a. a smaller oral dose b. a larger oral dose c. the same dose

Answer 47

b

Question 48

if a drug has a high first-pass effect, then switching from an oral dose to IV requires: a. a smaller IV dose b. a larger IV dose c. the same dose

Answer 48

a