Exam 8: Antifungal Agents Flashcards Preview

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Flashcards in Exam 8: Antifungal Agents Deck (22):
1

What are 5 drugs used for systemic mycosis?

Amphoteracin B
Ketoconazole
Miconazole
Fluconazole
Itraconazole

2

When is empiric anti fungal therapy used? What are two drugs that are used?

In seriously ill, neutropenic patients.
Amphoteracin B or Miconazole

3

What are drugs used to treat Candidiasis?

Amphoteracin B
-Azoles
Nystatin
Terbinafine

4

What are 4 mechanisms of anti fungal drugs?

1. Affect Membrane function (amphoteracin B)
2. Affect Cell wall synthesis
3. Affect Ergosterol synthesis
4. Affect nuclear division (Griseofulvin)

5

describe the synthesis of Ergosterol

Squalene is converted to Lanosterol by Squalene monooxygenase
lanosterol is converted to ergosterol by c14 alpha demethylase (p450)

6

Amphoteracin B formulation challenge

It is insoluble, but i administered parenterally somehow

7

What is the mechanism of amphoteracin B?

Affects membrane function
Binds to ergosterol in the cell membrane, which causes pores to form and loss of membrane integrity.

8

What are 2 adverse effects of Amphoteracin B?

1. Can also interact with human sterols, causing nephrotoxicity
2. It can cause anemia by decreasing erythropoietin production
These are both due to affects of sterols in the kidney

9

What are two non fungal infections that are treated with amphoteracin?

Leishmaniasis
Amebic meningoencephalitis (Naegleria fowler)

10

What are two types of -azoles? Which has a longer half life?

Imidazoles (2 nitrogens in the ring)
Triazoles (3 nitrogens in the ring)
Triazoles have a longer half-life

11

What are two triconazoles?

Itraconazole
Fluconazole
they have a longer half life (easier dosing)

12

What is the mechanism of -azoles?

Inhibition of 14 alpha demethylase that converts Lanosterol to Ergosterol
Disrupts the cell membrane

13

What are adverse effects of Ketoconazole?

Endocrine abnormalities (decreased androgen production)
They shut down steroid synthesis
they also inhibit p450 enzymes

14

How is fluconazole dosed?

once per day due to a pretty long half life

15

Griseofulvin mehcnaism

Disrupts mitotic spindle structure, arresting the cell in metaphase

16

how fast does griseofulvin work?

slowly, take weeks to months to work.

17

What is the mechanism of Nystatin?

Binds to sterols in the cell membrane (similar to amphoteracin B)
Disrupts cell membrane

18

How is nystatin used?

Topically, orally
Too toxic for parental use (as opposed to amphoteracin B)

19

Tolnaftate, Terbinafine mechanism

Inhibits squalene monooxygenase, inhibiting of Lanosterol...Ergosterol.

20

Caspofugin Mechanism

Inhibits B 1,3 glucansynthase (synthesis of glucans)

21

What is the use of Caspofugin?

Invasive cases of aspergillosis and esophageal candidiasis in patients who are refractory to other anti fungals
*** This is going to be on the test

22

What is the only specific use we have to know when it comes to anti fungals?

Caspofugin's