Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MLSCI 466 > Antimicrobials > Flashcards

Antimicrobials Flashcards

1
Q

Criteria for TDM

A
  • narrow therapeutic window
  • large inter patient variability (or intra)
  • method to use measure level (timely)
  • does not replace patient assessment and monitoring
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Why do we monitor anti microbial drug levels?

A
  1. Optimize serum levels
    - too low conctn = more susceptible organisms will be killed off while organisms with increased likelihood of resistance will survive => resistance and treatment failure
  2. Minimize toxicity
    - sustained high drug conctns put the pt at increased risk of experiencing adverse effects
  3. Research
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Vancomycin therapeutic window

A

Narrow!

<10mg/L = lacks effectiveness

> 20mg/L = toxic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Streptomyces orientalis

A

Vancomycin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What does vanc do?

A

Inhibits bacterial cell wall synthesis
- used to treat resistant GPB = CNS, S.aureus, Enterococcus

Very large molecule so makes it hard to pass across membranes = difficult to penetrate to site of infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Pharmacodynamics of vanc

A
  • slow kill = may even be bacteriostatic against some
  • inoculum dependent = less effective w larger inoculum
  • time dependent bacterial kill (AUC/MIC)
    > requires multiple blood draws
    > infusion would provide consistent AUC/MIC
    > maintaining trough levels 4-6x MIC appears ideal
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Red neck syndrome

A
  • vancomycin
  • more frequent with older prep
  • hypotension, flushing, upper body rash
  • minimize risk by increasing vol of infusion, slowing infusion rates
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Vancomycin nephrotoxciity

A
  • when it was impure = more prevalent
  • increased toxicity when combined with aminoglycoside
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

T or F. The higher the trough of vanc, the greater type chance of nephrotoxicity

A

T

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Ototoxicity

A

Vancomycin
- auditory nerve damage and hearing loss
- 80-100 mg/L
- current literature refutes the existence of this

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Monitoring vancomycin

A
  • routine levels no recommended
  • consider levels in select patients
    > deteriorating or unstable kidney functions
    > morbidly obese
    > therapy greater than 2 was
    > infants and children w serious infection
    > CSF infections
    > CF, burns (rapid clearance)
    > dialysis patients

draw trough level when pt is t steady state - before 5th dose usually

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When do we collect specimen for vanc trough level

A

30 mins or less before next dose
- first level at steady state and after at lest 2 MDs
dont rush= closer u wait, closer to steady state
**some pts may need level sooner = obes, high Rena function (peds)

Subsequent levels once/week

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Vancomycin at <10 mg/L trough

A

Decrease interval or increase dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Vancomycin at 10-20 mg/L trough

A

Target troughs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Vancomycin at > 20 mg/L trough

A

Increase interval or decrease dose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

When do we order random vanc levels?

A
  • pts with unstable kidney function
  • do not get regular doses of Van but rather get doses based on levels
    (Random levels until desired level then give another dose)
17
Q

Aminoglycosides

A

Gentamicin
Tobramycin
Alika in

18
Q

What do aminoglycosides target?

A

Gram negative active agents

19
Q

Dosing aminoglycoside

A
  • concentration dependent killing
    > more bacteria killed w high conctn
    > measure peak levels to assess efficacy
  • narrow therapeutic index
    > drug saturates in kidneys and auditory system
    > requires low drum level to diffuse back out an avoid toxicity (accumulation)
    > measure trough levels to minimize toxicity
  • optimize dosing w high doses and time to recover
    > conventional and extended interval
20
Q

Adverse effects of aminoglycosides

A

Nephrotoxicity - usually reversible
Ototoxicity - may be irreversible
> hearing loss, loss of balance
Risk factors:
- unadjusted doses, duration of treatment, hypovolemia, hypotension, other nephrotoxic/Ototoxic drugs

21
Q

T or F. AG nephrotoxicity is generally reversible

A

T
- usually occurs 5-7 days into treatment
- can even occur after D/C

Risk factors: duration of therapy, baseline renal function, other kidney insults, elevated trough leve;s

22
Q

T or F. Auditory Ototoxicity in AG is reversible

A

F! May be irreversible
- congenital mitochondrial dysfunction notable (avoid AG if toxicity reported on maternal side)
- warning: tinnitus, sense of fullness in ears

23
Q

Vestibular totoxicity

A
  • usually occurs 5-14 days after initiation of AG therapy
  • has occurred with IP, inhaled AG therapy
  • symptoms can happen independently of drug levels
24
Q

Symptoms of vestibular ototoxicity

A
  • disequilibrium: vertigo, nausea/vomiting, headache
  • oscillopsia: objects appear to move back and forth esp. with head movement
  • nystagmus: involuntary rapid eye movements
25
Q

When should patients on AG be told to watch and report signs and symptoms of ototoxicity

A

After seven days of therapy

26
Q

What is extended interval dosing

A
  • employs principles of concentration dependent kill and drug-free intervals
  • takes advantage of post-antibiotic effect
  • contraindicated = endocarditis, dialysis patient, cystic fibrosis
  • precautions: liver disease, pregnancy, severe renal dysfunction
27
Q

3 general classes of anti fungal (systemic)

A
  • Polynesian = amphotericin B
  • echinocandins= caspofungin, micafungin, anidulafungin
  • new triazoles = flucoazole, viconazole, etc.
28
Q

Invasive fungal infections mostly an issue in ….

A

Immunocompromised pts

29
Q

antifungal that may require TDM

A

amphotericin
- toxic; may qualify
- BUT cannot be monitored with blood/serum levels

30
Q

Voriconzole TDM?

A

nonlinear
evidence of association of effect and toxicity with levels

31
Q

therapeutic range for efficacy: antifungals

A

trough blood level more than 1 mg/L for clinical outcomes

32
Q

therapeutic range for toxicity of antifungals

A

trough blood level less than 5.5 mg/L for safety

33
Q

Voriconazole properties

A
  • active against lots of yeast and several mold infections
  • narrow ther index: 2-5.5 mcg/mL
  • well absorbed = 96% bioavail
  • highly metabolized by CYP2C19, CYP2C9, CYP3A4 = 8 metabolites
  • extensive tissue distribution
  • 80% of metabolites eliminated in urine
  • half-life = 6 to 12 hours
34
Q

other azoles where TDM applies:

A

itraconazole
posaconazole
isavuconazole

35
Q

voriconazole TDM recommendations

A
  • target range = 1.0 to 5.5 mg/L
  • level after 5-7 days on same dose
  • assay performed at UAH twice weekly on tandem MS
36
Q

T or F. Linear PK is much easier to manage for pts on antimicrobial therapy

A

T!

MLSCI 466 (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions