Antifungals Flashcards

1
Q

All fungi are ____ organisms

A

eukaryotic

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2
Q

2 types of fungal infections

A

systemic

superficial (cutaneous, subcutaneous)

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3
Q

Fungal infections are the __ most common nosocomial infection

A

4th

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4
Q

Patients at greatest risk for mycoses

A
  • surgical intensive patients
  • prosthetics
  • immunosuppressed
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5
Q

Fungi use _____ for cell membrane

A

ergosterol

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6
Q

Squalene is converted to ______ by _______

A

lanosterol

squalene epoxidase

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7
Q

Lanosterol is converted to _______ and catalyzed by _____

A

ergosterol

CYP450 (14a-sterol demethylase)

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8
Q

Amphotericin B/nystatin MOA

A

bind ergosterol
disrupt membrane stability
- pores, leakage
500x greater affinity for ergosterol

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9
Q

Amphotericin B fungistatic or fungicidal?

A

both!

depends on concentration and fungal sensitivity

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10
Q

Amphotericin B use

A
  • broad spectrum

- life threatening systemic mycoses

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11
Q

BBW amphotericin B

A

for proper use

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12
Q

Nystatin

A

swish and swallow

oral thrush

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13
Q

Adverse reactions of amp b/nystatin

A
  • infusion related effects (cytokine storm)
  • renal toxicity (proximal tube)
  • hematologic toxicity (myelosuppression in anemia –> decreased erythropoietin secretion)
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14
Q

cytokine storm

A

fever
chills
rigors
hypotension

** pretreat with APAP

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15
Q

Flucytosine MOA

A
  • Transported into fungal cells by cytosine permeate
  • Converted to 5FU by cytosine deaminase
  • 5FU converted to 5FdUMP and FUTP
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16
Q

Flucytosine fungistatic or fungicidal?

A

fungistatic

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17
Q

Flucytosine resistance

A

during mono therapy, so restricted use

- due to mutations of permeate and deaminase

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18
Q

Flucytosine use

A
  • cryptococcal pneumonia and meningitis

- systemic candidiasis

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19
Q

What drug is usually administered in combo with Amp B?

A

flucytosine

- synergistic

20
Q

BBW flucytosine

A

for dose reduction in patients with renal insufficiency

21
Q

Flucytosine adverse reactions

A
  • hematologic (BM suppression)

- hepatotoxicity

22
Q

DDI between flucytosine and Amp B

A
  • Amp B kidney damage, may suppress flucytosine excretion

- drugs that cause hematological toxicities

23
Q

Griseofulvin MOA

A
  • mitosis inhibitor
  • binds tubulin
  • drug accumulates in keratin precursor and binds tightly to keratin
24
Q

Griseofulvin fungistatic or fungicidal?

A

fungistatic

25
Q

Griseofulvin use

A
  • oral, dermatophytic infections of hair, skin, nails
  • ringworm
  • may take 6 months of treatment!
26
Q

Griseofulvin adverse reaction

A
  • headache in children
  • acute intermittent porphyria
  • photosensitive
27
Q

Terbinafine MOA

A

inhibit squalene epoxidase

28
Q

Terbinafine fungistatic or fungicidal?

A

fungicidal

29
Q

Terbinafine use

A
  • ringworm
  • onychomycosis (cannot penetrate into cuticle)
  • takes 3 months
30
Q

Terbinafine adverse reactions

A
  • well tolerated topically
  • skin reaction
  • dysgeusia
  • heapatotoxicity
31
Q

DDI terbinafine

A
  • inhibit CYP2D6, induces 3A4
32
Q

Fluconazole MOA

A

inhibit 14a sterol demtheylase

33
Q

Fluconazole fungistatic or fungicidal?

A

fungistatic

34
Q

Fluconazole triazole or imidazole?

A

triazole

35
Q

Triazoles or imidazole more selective for fungal CYP?

A

triazole

36
Q

Generalization of all 14a sterol demethylase inhibitors

A
  • important difference in anti fungal spectrum, PK and side effects
  • check susceptibility of organism
  • all equally effective against candida
  • oral BA varies
37
Q

Fluconazole use

A
  • crytpcoccal meningitis

- superficial mycoses

38
Q

Fluconazole adverse reaction

A
  • generally well tolerated
  • GI upset
  • hepatoxocitiy
  • NO pregnancy
39
Q

DDI fluconazole

A
  • inhibit CYPS
40
Q

Caspofungin MOA

A
  • non-competitive inhibitors of B1,3 D gluten synthesis
41
Q

Caspofungin fungistatic or fungicidal?

A

fungicidal

42
Q

Caspofungin use

A
  • aspergillosis
  • febrile neutropenia
  • severe candidiasis
43
Q

caspofungin adverse reactions

A

Almost none

44
Q

Which drugs are fungistatic?

A

Fluconazole
Griseofulvin
Flucytosine
Amp B

45
Q

Which drugs are fungicidal?

A

Terbinafine
Caspofungin
Amp B