Antifungal Drug Targets Flashcards

1
Q

Which of the following routes of antifungal administration is most suited to the treatment of a minor fungal infection of the toenail?

A

topical

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2
Q

Amphotericin works by

A

binding ergosterol and forming pores in the cell wall

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3
Q

Normal saline is infused in a patient receiving amphotericin B to:

A

diminish renal damage

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4
Q

Antifungal that most closely related to the anticancer drug 5-fluorouracil (5-fu).

A

flucytosine

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5
Q

Which 2 antifungals would most likely produce bone marrow suppression as an adverse effect?

A
flucytosine
ampho B (decreased EPO, thus associated with anemia)
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6
Q

Blurring and changes in color vision or brightness are most commonly associated with the use of:

A

voriconazole

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7
Q

Which organs are likely to be affected by flucytosine?

A

hepatic

GI

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8
Q

The imidazole drug, ketoconazole, is distinguished from the triazoles, like fluconazole, by its:

A

lower selectivity for fungal CYPs

more toxic to humans

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9
Q

Which antifungal possesses the broadest spectrum of anti fungal activity?

A

amphotericin B

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10
Q

Amphotericin liposomal formulations provide for:

A

diminished renal toxicity

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11
Q

Which antifungal would most likely give rise to gynecomastia and impotence in males

A

ketoconazole

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12
Q

Which of the following inhibits the production of ergosterol through a non-CYP mediated event? flucytosine, caspfungin, nystatin, posaconazole, terbinafine

A

terbinafine

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13
Q

Class of drug that affects CYP450

A

Azoles

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14
Q

This drug can be given intrathecally to fight meningitis (but is not really the first choice).

A

Ampho B

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15
Q

When given prophylactically, reduces fungal disease in BM transplant and AIDS patients

A

fluconazole

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16
Q

Drug shows reduced F when taken with rifamycins:

A

itraconazole

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17
Q

Interferes with microtubule function:

A

Griseofulvin

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18
Q

Deposited in newly forming skin where it binds to keratin, protecting skin from new infection

A

Griseofulvin

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19
Q

Drug interactions with warfarin and phenobarbital:

A

Griseofulvin

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20
Q

Commonly used for suppression of local candidal infections

A

Nystatin

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21
Q

Cause abnormalities in liver enzymes

A

AZOLES

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22
Q

Flucytosine has a ______ therapeutic window and a _____ spectrum

A

narrow; narrow

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23
Q

Widest therapeutic index of azoles

A

fluconazole

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24
Q

Treats dimorphic fungi (Histoplasma), Aspergillus, Coccidioides cryptococcus

A

itraconazole

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25
Q

Tx of choice for Aspergillus; Works well against Candida and dimorphic fungi

A

voriconazole

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26
Q

Inhibitor of CYP3A4, so dosage modification of many meds are required.

A

voriconazole

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27
Q

Broadest spectrum of azole family

A

Posaconazole

28
Q

Fungicidal by inhibiting synthesis of Beta(1-3)-glucan

A

Echinocandins

29
Q

Inhibits fungal enzyme squalene epoxidase (accumulation of sterol squalene is toxic)

A

Terbinafine

30
Q

How is amphotericin B administered?

A

IV; orally ONLY if you want to treat the GI lumen

31
Q

Why is liposomal ampho B more favorable?

A

preferential binding reduces toxicity, increases efficacy

drug can be released by fungal lipases

32
Q

2 mechanisms of ampho B resistance:

A
  1. altered sterol target

2. decreased ergosterol in membrane

33
Q

How do you decrease the infusion-related toxicity of ampho B?

A

slow infusion rate

decrease daily dose

34
Q

What toxicities are associated with Ampho B?

A

anemia (due to increased EPO)
renal
hepatic

(plus infusion-related– HA, fever, chills, NV, etc)

35
Q

Taken up in fungal cells by cytosine permease

A

flucytosine

36
Q

Inhibits fungal DNA/RNA synthesis

A

flucytosine (converted to FdUMP and FUTP)

37
Q

Why is flucytosine not used alone?

A

synergy with other drugs

resistance prevention

38
Q

Azoles inhibit fungi by:

A

reducing ergosterol synthesis via fungal CYP450 inhibition

39
Q

Most common azole side effect:

A

mild GI upset

40
Q

Prone to drug interactions in humans:

A

azoles (CYP450 inhibitors)

41
Q

Reduced bioavailability when taken with rifamycins

A

itraconazole

42
Q

Treats dimorphic fungi, dermatophytoses, onychomycosis

A

itraconazole

and perhaps voriconazole?

43
Q

Often given prophylactically to AIDS and BM transplant patients

A

fluconazole

44
Q

Good CSF penetration, good cryptococcal meningitis therapy

A

fluconazole

45
Q

May increase substrate levels of any cyclosporines, tacrolimus, and statins that are taken in conjunction due to CYP3A4 inhibition

A

voriconazole

46
Q

Best treatment for invasive aspergillosis

A

voriconazole

47
Q

Indicated for mucormycosis and prophylaxis of infections in chemo, BM transplant and graft-vs-host disease

A

posaconazole

48
Q

Disrupts cell wall by inhibiting beta(1-3)glycan synthesis

A

echinocandins

49
Q

Mostly used to treat candidal infections (only)

A

echinocandins

50
Q

Caspofungin (an echinocandin) and cyclosporine, when given together, cause:

A

elevated liver enzymes

51
Q

Anidulafungin may cause the release of _____ during IV infusion.

A

histamine

52
Q

Only used in systemic trx of dermatophytosis

A

griseofulvin

53
Q

Binds to keratin, protecting skin from new infection (fungistatic)

A

griseofulvin

54
Q

May cause allergic syndrome, hepatitis, drug interactions with warfarin/phenobarbital

A

griseofulvin

55
Q

Fungicidal keratin-binding drug

A

terbinafine

56
Q

Inhibits squalene epoxidase, which causes squalene accumulation and toxicity

A

terbinafine

this somehow affects ergosterol synthesis?

57
Q

Suppresses local candidal infections via topical prep

A

nystatin

58
Q

Topical clotrimazole and miconazole treat:

A

vulvovaginal candidiasis

59
Q

Inhibits fungal mitosis

A

griseofulvin

60
Q

Fungal drug class that causes QT prolongation

A

azoles

61
Q

Antifungal drug that causes cardiomyopathy

A

itraconazole

62
Q

Antifungal that is a substrate for and inhibitor of CYP2C19

A

voriconazole

63
Q

Antifungal class that inhibits ergosterol synthesis by blocking 14-alpha demethylase

A

azoles

needed to convert lanosterol to ergosterol

64
Q

What causes serum concentration variability when taking voriconazole?

A

gene polymorphisms

65
Q

Ketoconazole inhibits what mammalian process, thus causing unpleasant side effects

A

steroid synthesis