Vancomycin & Aminoglycosides

Front 1

formulation of vanco and which is perferred

Back 1

-iv
-po
-iv, bc po is not absorbed

Front 2

moa of vancomysin

pneumonic

Back 2

-cell wall inhibitor

• Inhibits stage 2 of bacterial cell wall synthesis (peptidoglycan synthesis and assembly) by binding to the D-alanyl-D-alanine terminus of cell wall precursor units

a van with + on its side is driving out of iv tubing and is going to run over a ear and hit ptg cell wall

Front 3

vanco spectrum of activity

Back 3

all gram + (aerobic and anaerobic)

-Staph aureus (including MRSA)
− Staph epidermidis (including MRSE)
− Streptococcus (including PCN resistant strains)
− Enterococcus (bacteriostatic, bactericidal if combined with gentamicin)
− Corynebacterium spp. (diphtheroids)
− Clostridium spp. (including C. difficile)

Front 4

vanco is static or cidal toward entercoccus

Back 4

static

Front 5

vanco +gentamicin is static or cidal toward entercoccus

Back 5

bacteriocidal

Front 6

synergistic + gentamicin protects vs

Back 6

-S. aureus (MSSA and MRSA)
-Enterococcus

Front 7

oral bioavail of vanco

Back 7

- F<5 %
-low

Front 8

when can you use po vanco

Back 8

-to treat C.difficle colitis

Front 9

t/f
you can use po form of vanco for systemic infections

Back 9

false, only use for c. difficle infxn

Front 10

vanco elimination?

Back 10

renal

Front 11

vanco t1/2=
vano t1/2 esrd=

Back 11

t1/2= 6-7 hrs
ESRD= 7 days

Front 12

dose adjust for vanco?
when?

Back 12

renal impairment

Front 13

during dialysis in what happens to vanco?

Back 13

-not cleared by hemodialysis or peritoneal dialysis, dnt need to give additional dosage after dialysis

Front 14

for vanco what concentrations are most accurate method to correlate to efficacy

Back 14

trough

Front 15

vanco

trough concentration should =? why

Back 15

>10 mg/ml
to prevent emrgence of vrsa/visa

Front 16

vanco

auc/mic =

Back 16

400
Newer evidence suggests that AUC/MIC is the important parameter: AUC:MIC > 400 is optimal
− If the MIC is 1, a target trough of 15-20 should be targeted to try to achieve the AUC:MIC > 400
− If the MIC is 2, it is unlikely that an AUC/MIC of 400 can be achieved

Front 17

vano is con indepen or depen drug

Back 17

both

Front 18

vanco therapeutic indications

Back 18

Infections due to MRSA, Staph epidermidis
• PCN-resistant Streptococci, Enterococci infections
• PO Vancomycin - Clostridium difficile colitis
• Patients infected with Gram + bacteria with allergy to β-lactam (PCN)
• Prophylaxis
− Surgical procedures involving prosthetic device or patient with recent MRSA infection
− Endocarditis prophylaxis per AHA

Front 19

CDC Recommendations for Preventing the Spread of Vancomycin Resistance:

Back 19

1. Treatment of serious infections caused by B-lactam-resistant gram-positive organisms

3. When antibiotic-associated colitis fails to respond to metronidazole therapy or is severe and
potentially life-threatening

5. Prophylaxis for major surgical procedures involving implantation of prosthetic materials or devices
at institutions that have a high rate of infections caused by MRSA or MRSE (one dose before
surgery is sufficient, repeat one dose if the procedure lasts >6 hours, NTE 2 doses total)

Front 20

b lactam vs vanco, greater killing effect?

Back 20

b-lactam,
vanco has slow bactericidal killing

Front 21

vanco iv admin
- how long is the usual infusion rate?
- inf rate of dose >1gm

Back 21

- at least 60 min
- doses >1 gm are generally infused over 1.5-2 hrs

Front 22

doall patient population get vanco loading dose?

Back 22

no, only with certain pop
- critically ill
-bacteremia
-endocarditis
-meningitis
-ostemyelitis,
-hospital acquired pneumonia

Front 23

vanco target trough varies based on

Back 23

-site of infection
- mic of the mrsa stain

Front 24

vanco target trough?
target for serious infections?

Back 24

target trough= 10-15 mg/L
target trough for serious infections =15-20 mg/L

Front 25

vanco peak
- max level
-aim level

Back 25

- below 60 mg/ L , to avoid ototoxicity
-aim <40 mg/L

Front 26

when do you get trough level for vanco?

Back 26

- get trough after the 4th dose (ss) in patients w/ normal renal fxn
- obtain the trough < 1 hr prior to nxt scheduled dose

Front 27

vanco trough monitoring is reco for

Back 27

-Patients receiving aggressive dosing,
-Patients at high risk of nephrotoxicity
-Unstable renal function
-Prolonged courses of therapy: >3-5 days

Front 28

how frequent do you monitor trough levels for vanco?

Back 28

- once weekly monitoring is reco for hemodynamic stable patients
- renal failure: random levels checked 3-5 days after initiating therapy

Front 29

vanco adr

Back 29

- drug fever
- red neck syndrome
-otoxicity
- nephrotoxicity

neph and otox like amg + red neck syndrome+ drug fever

Front 30

red neck syndrome

Back 30

-vanco
-caused by rapid infusion and high doses
- Sx: tingling and flushing of the face, neck and thorax, tachycardia, hypotension
− Prevent by infusing over at least 60 minutes (antihistamine also effective)
− Doses > 1 gram should be infused over 90-120 minutes
− Not an allergic hypersensitivity

Front 31

t/f
red neck syndrome is an allergic hypersensitivity rxn

Back 31

false

Front 32

is ototoxicity a main concern w/ vanco?

Back 32

-only 1-9%
- only occurs when taking other otoxic agents
- when tx is >21 days

Front 33

factors associated w/ nephrotoxicity when taking vanco

Back 33

-Trough >15
-Extended durations of therapy: > 2 weeks
-Concurrent nephrotoxins
-Obese patients (>101.4 kg)

Front 34

monotherapy w/ vanco will you get nephrotox?

Back 34

uncommon

Front 35

vanco preg cat

Back 35

C

Front 36

aminoglycosides (5)

Back 36

- streptomycin
-gentamicin
-tobramycin
-amikacin
-neomycin
-netilmicin

Front 37

amg moa

Back 37

-Inhibits bacterial protein synthesis by binding to 30 S ribosomal subunit misreading and premature
termination of translation of mRNA
• Entry into the cell
− Diffuse through the porin proteins in the outer membranes
-bactericidal

Front 38

amg resistance mechanisms

Back 38

1. Drug inactivation by microbial enzymes (acquired)
2. Impaired transport of drug into the cell (intrinsic)
3. Alterations in ribosomal structure (acquired)

Front 39

amg spectrum of activity

Back 39

- aerobic, GN bacilli ****
-heaps
- gram + cocci-limited
- mycobacteria (streptomycin,amikacin)

Front 40

amg covers what aerobic gram - bacilli

Back 40

- Haemophilus spp
− Enterobacteriaceae
− Serratia spp: gentamicin is most active
− Pseudomonas aeruginosa: tobramycin is most active
− Acinetobacter spp

HEAPS

Hint 40

think heaps

Front 41

amg are concentration indep or depen?

Back 41

concentration dependent bactericidal activity
-higher concentation, the greater the rate of bacteria killing

Front 42

can you get pae with gram + or -?

Back 42

get pae only with gram -

Front 43

explain the pae of amg

Back 43

inc dose --> inc concentation of amg
--> long pae effect

Front 44

duration of pae depends on multiple factors

Back 44

-Type of organism
-Type of antimicrobial agent
-Concentration of antimicrobial (correlates with peak and AUC) -Duration of exposure

Front 45

amg
def adaptive resitance and how to prevent this

Back 45

-initial drug concentration is subtherapeutic, bacterial uptake of drug is reduced upon 2nd exposure
resulting in slower bactericidal activity
- prevent this by giving a loading dose

Front 46

amg

how do you get synergy

Back 46

Results in more than additive effect when combined with β-lactams (GN and GP)

Front 47

Amg are active vs gram + cocci on their own?

Back 47

no, have to be combined with cell wall active agent (B-lactam, pcn, vanco)

Front 48

amg

which agents are vs mycobacteria

Back 48

- streptomycin
-amikacin

Front 49

amg

absorption

Back 49

-less than 1% absorbed from the gi tract
-absorption after im injection is rapid and complete
-usually given iv

Hint 49

think of birthday cake
tag

Front 50

amg distribution
- high
- approx equal
-low

Back 50

high: renal cortex, inner ear

approx equal: pleural, synovial, peritoneal

low: bile, respiratory

Front 51

amg vs vanco dialysis

Back 51

Dosing must be adjusted for decline in renal function
− ~50% removal in 12 hour by hemodialysis
− Peritoneal dialysis less effective than hemodialysis in AG removal

Front 52

gent/tobra peak

Back 52

5-10 mg/L

Front 53

Amikacin peak

Back 53

20-35 mg/L

Front 54

for amg peak mean

Back 54

assure efficacy

Front 55

trough
gent/tobr
amikacin

Back 55

gent= 0.5-2 (aim for less <1)
amikacin= 5-10

Front 56

amg synergy dosing

-gentamycin
-target peak

Back 56

Synergy dosing: used for GP bacteria and urinary tract infections (not pyelonephritis or urosepsis)
− Gentamicin 1.0 mg/kg Q8H
− Target Peak 3-5 mg/L, Trough <1 mg/L
− Goal Minimize toxicity without jeopardizing clinical cure

Front 57

extended interval dosing for amg is not reco for who?

Back 57

-Meningitis, endocarditis, enterococcal and staphylococcal infections, neutropenic patients
− Children
− Hyperkinetic patients: burn victims, spinal cord injury, pregnancy
− Renal impairment: CrCL <20 ml/min, dialysis

Front 58

amg are reco for kids

Back 58

no, pregnancy category D

Front 59

adr of amg

a mean guy in the eigth round delivers a crushing left hook to his opponets ear, with his opponent off balance, a mean guy surges upward with a savage right hook into his left side, pulverizing his kidney (renal toxicity), the opponents drops to the floor out cold in a complete neuromuscular blockage

Back 59

- ototoxicity
- nephrotoxicity
-neuromuscular paralysis

Front 60

can a pt use amg if they have myasthenia gravis

Back 60

- no, it is a contraindication

Front 61

amg preg cat

Back 61

D

Front 62

which amg is most active vs serratia

Back 62

gentamycin

Front 63

which amg is most active vs psa

Back 63

tobramycin