Naplex Pk

Front 1

Vancomycin trough

Back 1

5-10

Front 2

ABW

If the actual body weight is greater than 25% of the calculated IBW, calculate the adjusted body weight

Back 2

IBW + 0.4(Total body weight - IBW)

Front 3

When is it most appropriate to check drug plasma concentrations

Back 3

steady state

Front 4

How many half-lives does it take for a drug to be almost completely eliminated

Back 4

4-5.

equivalent to 6.25%-3.125% of drug remaining in the body. After 7 half lives <1%

Front 5

What determines half-life

Back 5

clearance (Cl) and volume of distribution (Vd)

half-life = 0.693Vd / Cl

Front 6

What determines elimination constant

Back 6

Cl and Vd

ke = Cltb / Vd

Front 7

What SrCr values give a better estimate of renal function for elderly with low SrCr (<0.8mL/ming)?

Back 7

1mg/dL

Front 8

When is a trough taken?

Back 8

30 mins before next dose

Ideally this trough would be equal to Cpmin. If trough is drawn earlier than right before the next dose:

Cpmin = observed Cp trough x e^(Ke*time)

Front 9

When is a peak taken?

Back 9

30 mins after a 30-min infusion

Cpmax = measured Cp peak / e^(Ke*time)

where time is the difference between the time of the end of infusion and the time of the measured Cp

Front 10

Antibaterial activity of aminoglycosides: time or concentration dependent killing?

Back 10

concentration.

Optimal batericidal activity is achieved when peak concentration is about 10 times MIC

Higher peak = better clinical outcome

Front 11

PAE

- varies with organism and concentration
- greater for gram neg. than gram pos.
- increases with increasing aminoglycoside peak concentrations

Back 11

prominent postantibiotic effect

Front 12

gram positive

Back 12

serious infections e.g. endocarditis, sepsis

Front 13

population Vd and t1/2 for gentamycin and tobramycin

Back 13

Vd ~ 0.3L/kg (will be higher in pregnant, critically ill, ascites, CHF pts)
t1/2 ~ 2h

Front 14

When is it beneficial to give LDEI

Back 14

less toxic, less monitoring, less costly. also easier to convert to home IV therapy

Large dose extended interval dosing allows kidneys to recover from nephrotoxic effects of AGs. Efficacy will not be compromised because of PAE.

Front 15

Who is eligible for LDEI

Back 15

good renal function.

AVOID in pts with altered Vd, pregnant, critically ill, quadriplegics, ascites, CF, renal dysfunction CrCl <20mL/min, ESRD on hemodialysis or CAPD

Front 16

Gentamycin/tobramycin Cp max and Cp min

Back 16

Cpmax = 15-20mcg/mL
Cp min <1mcg/mL or undetectable

gentamicin MIC for pseudomonas aeruginosa is usually ~ 2mcg/mL, so desired Cmax is about 20mcg/mL.

Front 17

Gentamycin/tobramycin drug-free period

Back 17

Optimally, 4 hours <0.5mcg/mL

Front 18

gentamicin/tobramycin empiric dosing

Back 18

gram neg: 5-7mg/kg/dose
gram pos: 3mg/kg/dose

CrCl>60: Q24h
>40: Q36h
>20: Q48h

Front 19

gentamicin/tobramycin monitoring

Back 19

Peak: random level 8-12 after 1st dose. 30 mins after second 30-minute infusion

Trough: 24h after 1st dose. continue regimen if <1mcg/mL

Front 20

gentamicin/tobramycin target concentrations (with conventional dosing)

Back 20

Cpmax
synergy for gram pos: 3-4mcg/mL
gram neg: 6-8mcg/mL (UTIs, bacterimia, pneumonia, sepsis)
cystic fibrosis: 8-12mcg/mL

Cpmin: <1-2mcg/mL

Front 21

gentamicin/tobramycin empiric therapy

Back 21

Loading IV bolus dose: 2mg/kg i.e. desired plasma conc x Vd

Interval: (lnCpmax - lnCpmin) / ke...which is 0.0293*CrCl+0.01...+ infusion time in hr.
Interval is usually ~ 3 t1/2s

Maintainence: they are A-holes if they want you to calculate this without a log-function calculator. So the answer is A.

Front 22

gentamicin/tobramycin monitoring

Back 22

WBC
temperature
cultures
infection s&S
peaks especially if aggressive targets are used (peak of 8mcg/mL or trough of 2mcg/mL)

BUN/SCr/UO
ototoxicity
troughs

Front 23

gentamicin/tobramycin steady state

Back 23

4 SrCrs is about one half-life. So steady state is about 4*SrCr *4 = 16*SrCr.

Front 24

amiodarone

Back 24

blue syndrome
3A4 inhibitors
check thyroid function

Front 25

1c

Back 25

blocks Na

Front 26

3

Back 26

can use in CVdz

Front 27

sotalide

Back 27

only for maintainence

Front 28

dofetalide

Back 28

quickest onset, dose based on CrCl and QTc

blocks K+ from reentering
AVOID using with HCTZ

Front 29

1st afib <48h

Back 29

rhythm

Front 30

ibut

Back 30

IV, most stay in hosp>3d for obs

Front 31

2a

Back 31

amiodarone

Front 32

QTc prolongating drugs

(>440 msec)

Back 32

quinidine (also causes D)
procainamide (also causes lupu)