Antifungals

Question 1

superficial fungal infections

Answer 1

• skin, hair, nails
• bugs: trycophyton, microsporum, epidermophyton
• scalp= tinea capitis
• beard= tinea barbae
• foot= tinea pedis

Question 2

opportunistc fungal infections

Answer 2

• aspergillosis (mold)
• mucormycosis (mold)
• cyptococcosis (yeast)
• candidiasis (yeast) –> 4th most common nosocomial

Question 3

amphotericin B (mech, resistance(

Answer 3

• broad spectrum antifungal –> used in SEVERE, immunocomp
• MOA= holes in ergosterol containing membranes
• MOR= produce less ergosterol, or have thicker membranes
• give IV (poor oral)
• intrathecal for CSF

Question 4

adverse reaction of amphotericin B

Answer 4

• infusion related toxicity –> fever, phlebitis, HA, hypotension
• IV saline/ hydrocortisone before infusion
• type I RTA
• anemia (effects kidneys, EPO)
• hypomagnesemia

Question 5

uses of amphotericin B

Answer 5

• rapidly progressing fungal infections

- cryptococcus –> combine with flucytosine, follow with fluconazole

Question 6

name some azoles

Answer 6

imidazole= ketoconazle
triazole= itra, vori, posa, isavu

Question 7

MOA/ MOR of azoles

Answer 7

MOA= inhibit ergosterol biosynth by blcok conversion of lanosterol

MOR= efflux pumps, target mutation

Question 8

absorption/dist/metab of ketoconazole and itraconazole

Answer 8

good oral —> antacids hinder absoprtion

• dist to keratinocytes and vag secretions
• hepatic metabolism

Question 9

what is itraconazole generally used for?

Answer 9

dimorphic fungi

-broader spectrum triazole

Question 10

keto/itraconazole toxicity

Answer 10

• p540 inhibitor
• gynocomastia
• GI disturbance

Question 11

fluconazole

Answer 11

-good oral absorption
-CSF!!
-renal excretion –> loooooong t1/2 (25h)
-generally well tolerated
but TERATOGENIC
-p450 inhib

Question 12

two big uses of fluconazole?

Answer 12

cryptococcal meningitis (AIDS)
cociidiodal meningitis

Question 13

newer azoles….

Answer 13

• vori, posacon, isavuc
• good oral availability + good dist
• hepatic excretion
• long t1/2

Question 14

use: voriconazole, isavuconazole

Answer 14

Vori= aspergillosis
-visual disturbances

isavuc= mucormycosis

Question 15

caspofungin (echinochandin)

Answer 15

• MOA= inhibits formation of b-1-3-D-glucan (part of cell wall)
• MOR= mutation in large subunit of FKS1 gene (13bDgluc)
• uses: invasive aspergillosis (static), candidiasis (cidal)

NOT crypto

Question 16

echinocandin absorp/dist/metab/tox

Answer 16

-IV
-good dist
-Hepatic metab, fecal excretion
-tox= GI upset, HA, ***skin rash
CAT C pregnancy

Question 17

flucytosine

Answer 17

inhibits DNA synth: C–> U

• mammals lack cytosine deaminase
• combine with ampho B in severe infx
• good CSF dist –> CNS infx
• renal excretion
• can cause bone marrow depression in AIDS patients

Question 18

griseofulvin

Answer 18

• disrupt mitotic spindle by binding to MT/ tubulin
• static against DERMOPHYTES (not deep infx)
• poor oral absorption –> accum in kertin precursor cells

Question 19

terbinafine

Answer 19

• blocks ergosterol synth by inhibiting squalene epoxidase
• cidal
• dermatophytes