Antifungals

Question 1

Drug inhibits fungal membrane fxn? Binds ergosterol & forms membrane pores to allow electrolyte leakage.

Answer 1

Amphotericin B

Question 2

Drug inhibits fungal cell wall synthesis by inhibiting Beta-glucan synthesis?

Answer 2

Caspofungin

Micafungin

Question 3

Drug inhibits fungal nucleic acid synthesis?

inhibits DNA & RNA biosynthesis by conversion to 5-FU via cytosine deaminase.

Answer 3

Flucytosine

Question 4

Drug inhibits fungal lanosterol synthesis by inhibiting enzyme squalene epoxidase?

Answer 4

Naftifine

Terbinafine

Question 5

Drug inhibits fungal ergosterol synthesis? Via inhibition of p-450 that converts lanosterol to ergosterol.

Answer 5

Fluconazole
Itraconazole
Voriconazole
Miconizole
Clotrimazole
Ketoconazole

Question 6

use of Ampho B?

Answer 6

serious systemic mycoses
Cryptococcus, Blastomyces, Coccidioides, Histoplasma, Candida, Mucor.
used intrathecally for fungal meningitis

Question 7

What must you supplement in Ampho B?

Answer 7

K & Mg

bc of altered renal tubule permeability

Question 8

Toxicity of Ampho B?

Answer 8

fever, chills, hypotension, nephrotoxicity, arrhythmias, anemia, IV phlebitis

• hyrdate - reduce nephrotoxicity
• use liposomal Ampho to dec toxicity

Question 9

drug that topically forms membrane pores in ergosterol?

Answer 9

Nystatin

Question 10

Use of nystatin

Answer 10

oral candidiasis, diaper rash, vaginal candidiasis

too toxic for systemic use

Question 11

use of azoles?

Answer 11

local & less serious systemic mycoses.
fluconazole = chronic cryptococcal meningitis in AIDS tx
Itraconazole = blasto, coccidio, histo
Clotrimazole & miconazole = topical fungal infxn

Question 12

toxicity of azoles?

Answer 12

testosterone synthesis inhibition
(gynecomastia & impotence)
liver dysfunction (inhibits p-450)

Question 13

Toxicity of Flucytosine?

Answer 13

BM suppression

Question 14

Use of Flucytosine?

Answer 14

systemic fungal infxns (esp Cryptococcus) in combo with ampho B

Question 15

Clinical use of Caspofungin?

Answer 15

invasive aspergillosis

candida

Question 16

toxicity of Caspofungin?

Answer 16

GI upset

flushing (histamine release)

Question 17

Terbinafine clinical use?

Answer 17

dermatophytoses & onchomycosis

Question 18

toxicity of terbinafine?

Answer 18

abn LFTs

visual disturbance

Question 19

MOA of Griseofulvin?

Answer 19

inhibits MT fxn = disrupts mitosis

deposits in keratin-containing dissues

Question 20

Use of Griseofulvin?

Answer 20

superficial infxn (oral)
inhibit dermatophyte growth

Question 21

toxicity of Griseofulvin?

Answer 21

inc P-450 (therefore inc warfarin metabolism), teratogenic, carcinogenic, confusion & HA

Question 22

Antiprotazoan tx notes

Answer 22

pyrimethamine = toxoplasmosis
suramin & melarsoprol = t. brucei
nifurtimox = t. cruiz
sodium stibogluconate = leishmaniasis
atovaquin = babesiosis

Question 23

MOA of chloroquine?

Answer 23

blocks heme detoxification into hemozoin.

heme accumulates and is toxic to plasmodia

Question 24

Clinical use of chloroquine?

Answer 24

Plasmodium– malariae, viviax, ovale (NOT falciparum– resistant bc membrane pump)

Question 25

treat P. falciparum

Answer 25

atovaquone/ proguanil or mefloquin

Question 26

Quinidine use?

Answer 26

life-threatening malaria

Question 27

if hypozoite form– add which drug?

Answer 27

Primaquine

why? bc chloroquine doesnt work on latency in p. vivax & p. ovale forms.