Anti-Fungals

Question 1

How does Echinocandins (caspofungin) work?

Answer 1

Inhibits 1,3-B-glucan synthase which inhibits glucan synthesis which inhibits cell wall synthesis

Question 2

What makes Echinocandins (caspofungin)? And how is it administered?

Answer 2

1. Glarea Lozeyensis

2. IV

Question 3

What is Echinocandins (caspofungin) used to treat?

Answer 3

Amp-B resistant/invasive Aspergillosis. Esophageal Candidiasis. Pnuemocystis pneumonia

Question 4

What is the mechanism of action of Griseofluvin?

Answer 4

binds fungal tubulin which interferes with microtubule functioning disrupting cell division and inhibiting mitosis
- targets keratin

Question 5

What is Griseofluvin made from?

Answer 5

Penicillium Griseofluvin

Question 6

What is Griseofluvin used to treat?

Answer 6

dermatophytes (taenia infections) especially athlete’s foot

Question 7

Important points about Griseofluvin

Answer 7

• teratogenic

* increases CYP 450 metabolism- leading to increased effects of other drugs

Question 8

M.O.A. of polyenes

Answer 8

bind ergosterol creating holes in fungi cell membrane

Question 9

What is the mechanism of resistance towards polyenes?

Answer 9

Some fungi have decreased amounts of ergosterol in their cell membranes

Question 10

How are possible side effects of polyenes?

Answer 10

nephrotoxicity and anemia

Question 11

Key Points about Amphotericin B

Answer 11

“Big gun” and broad spectrum. type of polyene. works by binding to ergosterol causing pores and a leaky membrane (Na+, K+, and CA2+). made from: streptomyces nodosus. IV only- can be very toxic b/c it partially binds to host cholesterol and b/c it’s poorly absorbed from GI

Question 12

Key points about Nystatin

Answer 12

polyene. works by binding to ergosterol and making pores in cell membrane. Made from: streptomyces noursei. No IV (topical for local infection. or swish and spit for oral thrush)- b/c poor systemic absorption

Question 13

What is the Anti-metabolite drug and what is its M.O.A.?

Answer 13

1. Flucytosine

2. blocks thiamine synthesis thus blocking RNA and DNA synthesis.

Question 14

Key points about Flucytosine

Answer 14

Oral. used to treat: candida and cryptococcus neoformans ( used with Amp-B to treat cryptococcal meningitis)
- can lead to decreased: WBCs and Platelets. possibly= leukopenia and thrombocytopenia

Question 15

Azoles M.O.A.

Answer 15

inhibit cytochrome P450 14-alpha demethylase which prevents ergosterol synthesis b/c lanosterol cannot become ergosterol. Thus preventing cell membrane synthesis
*azoles are broad spectrum

Question 16

Which drugs are Imadizoles (type of azole)? And what is unique structurally?

Answer 16

1. ketoconazole and Miconazole

2. 5 membered ring with 2 Nitrogen groups

Question 17

Which drugs are triazoles (type of azole)? And what is unique structurally?

Answer 17

1. Itraconazole, Clotrimazole, fluconazole, and variconazole

2. 5 membered ring with 3 Nitrogen groups

Question 18

Describe Ketoconazole

Answer 18

broad spectrum imadizole (azole). inhibits ergosterol formation.

Question 19

decribe miconazole

Answer 19

imadizole (azole) used for dermatophytes. inhibits ergosterol formation.

Question 20

Describe Itraconazole

Answer 20

broad spectrum triazole (azole) used for candidiasis and systemic infections. inhibits ergosterol formation

Question 21

Describe Clotrimazole

Answer 21

Triazole (azole) used for topical and vaginal infections. inhibits ergosterol formation

Question 22

Describe Fluconazole

Answer 22

Triazole (azole). *Has the highest CSF penetration. Use after initial use of Amp-B and flucocytosine. inhibits ergosterol synthesis.

Question 23

Describe Variconazole

Answer 23

triazole (azole). *has highest oral bioavailability.

Question 24

Key points about Azoles

Answer 24

includes Imidazoles and Triazoles. largest group of anti-fungals. broad spectrum. can interact with CYP450 (which can impair drug detox. and steroid hormone synthesis and potentiate effects of other drugs). may cause gynecomastia in males.

Question 25

How is resistance developed to azoles?

Answer 25

some Fungi have pumps which pump out the azoles

Question 26

Allylamines M.O.A.

Answer 26

inhibit squalene epoxidase so squalene cannot become lanosterol thus inhibiting ergosterol synthesis/cell membrane synthesis.

Question 27

Key points about Allylamines

Answer 27

used for: superficial fungal infections. Take: orally or as topical cream. Terbinafine= allylamine that we need to know.