Antifungals Flashcards Preview

Ther 201 LE 3 > Antifungals > Flashcards

Flashcards in Antifungals Deck (32):
1

Cause of increased incidence and severity of fungal infections

1. surgery in deeper parts of the body
2. nonspecific cancer treatment knocking out immune system
3. intubation
4. increased use of broad-spectrum antibiotics
5. HIV -> immunocompromised

2

Usual fungal infection location

skin and mucous membranes, local or superficial mycosis

3

infection with pneumonia which spreads to heart, lungs, brain, kidneys via bloodstream

Invasive Aspergillosis

4

deep fungal infection that may affect the brain, orbit and cheekbones

Mucomycosis

5

Ideal Antifungal Properties

1. selectively eliminates funal pathogens from a host with minimal toxicity
2. fungistatic/cidal
3. affects funal cell wall/membrane

6

Antifungal classification due to use

Systemic: systemic infections
Oral or Topical: mucocutaneous

7

Antifungal classification due to chemical structure

Polyenes
Azoles (imidazoles, triazoles)
Anti-metabolites
Allylamines
Echinocandins
Morpholines

8

Polyene MOA

interacts with sterols in cell membrane, forming channels through which small molecules and ions leak from the inside to outside of fungal cell; FUNGICIDAL

9

Sterol in fungal cell wall

ergosterol

10

Polyene examples

Amphotericin B
Nystatin
Natamycin

11

Azole MOA

inhibit cytochrome P450-dependent enzymes (C14-demethylase) involved in biosynthesis of ergosterol

12

most common type of anti-fungal in practice

Azole

13

Azole examples

Fluconazole
Itraconazole
Ketoconazole

14

Azole general clincial use

for systemic fungi (dermatophytes)
fungistatic
broad spectrum

15

resistance to azole may develop by

-alteration of demethylase
-enhanced removal from the fungal cell

16

most common adverse effect of azoles

gastrointestinal upset (minor)

17

(imid)azole prototype

Ketoconazole

18

Ketoconazole mode of administration

orally
topically (mainly)

19

prereq of Ketoconazole to effect

acidic environment; doesn't enter CNS well

20

how is Ketoconazole distinguished from Triazoles

greater propensity to inhibit mammalian cytochrome p450; less selective for fungal P450

21

more currently used for system fungal infections

triazoles
-fluconazole
-itraconazole

22

T/F fluconazole is not metabolized

T; excreted unchanged

23

Fluconazole is mainly used for treatment of ______

mucocutaneous candidiasis

24

Itraconazole is the choice of treatment for diseases due to:

1. dimorphic fungi histoplasma
2. Blastomyces
3. sporothrix
dermatophytoses, onychomycosis

25

Azole of choice for Blastomycoses

Itraconazole

26

Itraconazole modes of administration

oral and IV

27

important drug interaction with itraconazole

Rifampicin! reduces bioavailablity of itraconazole

28

azole of choice for aspergillosis and mode of administrations

Voriconazole
IV, orally

29

azole used for invasive candidiasis, aspegillosis and Zygomycetes

Posaconazole

30

T/F Posaconazole can be given IV

F; only oral available

31

Drug interaction possibility of Posaconazole

Inhibits CYP3A4

32

Example of Anti-metabolite

Flucytosine (5-FC)