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Flashcards in Anti-fungals Deck (22):
1

Which drugs inhibit ergosterol synthesis?

azoles, terbinafine

2

Which drugs treat onychomycosis?

fluconazole, itraconazole, terbinafine

3

Which drugs inhibit cyt P450?

azoles, esp ketoconazole

4

Which drugs cause liver dysfunction?

azoles, griseofulvin

5

Describe the formation of ergosterol for fungal membranes.

Squalene-->lanosterol via squalene epoxidase
lanosterol-->ergosterol

6

Describe the formation of nucleic acids in fungus.

precursors-->pyrmidines-->nucleic acid

7

What is the basic MOA of the following anti-fungals?
azoles
terbinafine
flucytosine
griseofulvin
amphotericin B
nystatin

azoles-->inhibit lanosterol-->ergosterol
terbinafine-->inhibits squalene epoxidase
flucytosine-->inhibits DNA/RNA synthesis after becoming 5-FU
griseofulvin-->inhibits microtubule formation
amphotericin B-->forms holes in ergosterol membrane
nystatin-->forms holes in ergosterol membrane

8

What are the important things to know about amphotericin B?

binds ergosterol and forms holes in membrane
allows leakage of electrolytes
good for systemic mycosis, like cryptococcus meningitis

SE:
nephrotoxicity!
fever/chills
hypotension, hypokalemia
arrhythmias
phlebitis

9

How can you help decrease the nephrotoxicity while taking amphotericin B?

hydrating
taking w/ lipophilic version of amphotericin

10

What are the important things to know about nystatin?

forms holes in ergosterol membrane
VERY potent, so only approved for use topically

used for oral candida, vulvovaginitis, diaper rash

11

What are the important things to know about flucytosine?

flucytosine-->5-FU via cytosine deaminase
5-FU inhibits RNA/DNA synthesis
used w/ amphotericin B for cryptococcal meningitis

can cause bone marrow suppression

12

What do you need to know about the azoles?

inhibits synthesis of ergosterol
inhibit CYTp450-->can cause liver dysfunction and elevated liver enzymes
can mess w/ hormones-->ketoconazole: gynecomastia

13

What are the topical azoles?

clotrimazole
miconazole

14

What are the typical indications for fluconazole?

cryptococcal meningitis, candida

15

What are the usual indications for itraconazole?

blastomyces, coccidioides, histoplasma (dimorphic)

16

Which of the azoles can be used to treat aspergillus?

voriconazole

17

Which one of the azoles can be used for refractory fungi?

posaconazole

18

What are the important things to know about terbinafine?

inhibits squalene epoxidase, decreases ergosterol synthesis
dermatophytoses

19

What is good to know about echinocandins?

inhibits cell wall synthesis by inhibiting formation of beta glucan
**caspofungin, anidulafungin, micafungin
**can cause GI, flushing

20

What are the indications for caspofungin?

C-candida, ASP-aspergillosis Fungin

21

What's the deal with griseofulvin?

interferes w/ microtubule formation
disrupts mitosis
goes to keratin-containing tissues, so it is good for skin infections and tinea

22

What are the side effects of griseofulvin?

teratogenic
carcinogenic
confusion
HA
increases Cytp450 and can increase warfarin metabolism