antifungals Flashcards Preview

IDMM > antifungals > Flashcards

Flashcards in antifungals Deck (23):
1

list the antifungal classes

1. polyenes
2. azoles
3. echinocandins
4. terbinafine
5. griseofulvin
6. topical antifungals

2

list the polyenes

amphotericin B

nystatin

3

list the azoles

fluconazole

itraconazole

voriconazole

prosaconazole

4

list the echinocandins

corspofungin

andidulafungin

micafungin

5

list the topical antifungals

azoles: cotrimazole
hydroxy pyridones: ciclopirox
thiocarbamate: tolnafate

6

azoles MOA

inhibit synthesis of ERGOSTEROL via inhibition of lanosterol C14-demethylase

inhibits CELL WALL SYNTHESIS

protens CYP450 INHIBITOR

7

indications for azoles

UNCOMPLICATED systemic infections in immunocompromised patients

CANDIDA (fungistatic)
aspergillus (fungicidal)
CRYPTOCOCCUS
blastomycosis
coccidioimycosis
histoplasmosis

8

why is fluconazole good for UTIs?

because it is renally eliminated and achieves reliable urinary concentration

9

which drug causes phototoxicity

voriconazole (azole)

10

what is a consideration with azoles RE: interactions

azoles are potent CYP3A4 inhibitors

11

echinocandin MOA

inhibit synthesis of GLUCAN SYNTHASE which is an essential component of cell wall synthesis

inhibition of glucan synthase weakens the fungal cell wall and results in lysis

12

echinocandin indications

for SEVERE INVASIVE CANDIDA (on which it is fungicidal)

aspergillis infection (fungistatic)

NOT renally eliminated
IV admin only
caspofungin requires hepatic dosage adjustment

13

polyenes MOA

bind to ERGOSTEROL in cell membrane resulting in development of PORES in fungal membrane

this disrupts the cell wall permeability and results in cell death

14

polyenes indications

serious, INVASIVE/SYSTEMIC fungal infections

Amphotericin B: poor CSF penetration but effective for aspergillus, invasive candida and cryptococcal meningitis

Amphotericin B: vitreal and urine penetration--NOT renally eliminated--IV only

Nystatin: good for candida--local/topical only because HIGHLY TOXIC in IV form

15

terbinafine MOA

inhibits ERGOSTEROL synthesis via inhibition of SQUALENE OXIDASE

distrubutes mainly to sebum and skin

16

terbinafine indications

ONCHOMYCOSIS

used for fungal nail infections

17

what is a consideration with terbinafine RE: interactions

it is a potent CYP2D6 inhibitor

18

griseofulvin MOA

binds to TUBULIN and therefore interferes with microtubule formation and INHIBITS MITOSIS

binds to KERATIN in keratin precursor cells making them resistant to fungal infections

19

griseofulvin site of action/administration

ORAL ONLY

no topical action

20

what is a consideration with griseofulvin RE: interactions

it is a potent CYP450 INDUCER

21

how do topical azoles work

i.e cotrimazole

inhibits ergosterol synthesis

22

how do topical hydroxypyridones work

i.e ciclopirox

inhibits transport and uptake of essential substrates into the fungal cell

23

how do topical thiocarbamates work

i.e tolnafate

inhibits ergosterol synthesis via inhibition of squalene oxidase