Week 2 - Antifungals Flashcards
1
Q
Are fungi autotrophic (produce their own food)?
A
NO, fungi feed on dead things
2
Q
Amphotericin B
- Class
- MOA
- Spectrum
- Toxicity
- Resistance
- Distribution
A
- Polyene
- Fungicidal - Binds ergosterol, creates holes in membrane
- Broad, Yeast and molds
- TOXIC (binds cholesterol), Nephrotoxicity
- Rare, decreased ergosterol in membrane
- Small fraction excreted, long tissue half life, can cross BBB
3
Q
Nystatin
- Class
- MOA
- Spectrum
- Toxicity
- Resistance
- Distribution
A
- Polyene (topical)
- Fungicidal - binds ergosterol - creates holes
- Broad: yeast & mold
- TOXIC (binds cholesterol) - nephrotoxicity
- Rare, decreased ergosterol in membrane
- Small fraction excreted, long tissue half life, can cross BBB
4
Q
Fluconazole
- Class
- MOA
- Spectrum
- Toxicity
- Resistance
- Distribution
A
- Azoles
- Fungistatic: binds Erg11 - blocks production of ergosterol
- Most widely used antifungal
- Drug-drug interactions, hepatotoxicity, neurotoxicity, Avoid if PREGNANT
- Altered cyt p450, efflux
- orally available
5
Q
Itraconazole
- Class
- MOA
- Spectrum
- Toxicity
- Resistance
- Distribution
A
- Azoles
- Fungistatic: binds Erg11 - blocks production of ergosterol
- Most widely used antifungal
- Drug-drug interactions, hepatotoxicity, neurotoxicity, Avoid if PREGNANT
- Altered cyt p450, efflux
- orally available, acid/cola helps facilitate absorption
6
Q
Ketoconazole
- Class
- MOA
- Spectrum
- Toxicity
- Resistance
- Distribution
A
- Azoles
- Fungistatic: binds Erg11 - blocks production of ergosterol
- Most widely used antifungal
- Drug-drug interactions, hepatotoxicity, neurotoxicity, Avoid if PREGNANT
- Altered cyt p450, efflux
- orally available, acid/cola helps facilitate absorption
7
Q
Terbinafine (Lamisil)
- Class
- MOA
- Spectrum
- Toxicity
- Resistance
A
- Allylamines
- Fungicidal - inhibits squalene epoxidase
- Dermatophytes
- Topical, drug interactions with CYP2D6 substrates
- Rare
8
Q
Flucytosine (5-FC)
- Class
- MOA
- Spectrum
- Toxicity
- Resistance
- Distribution
A
- Nucleic Acid Synthesis Inhibitor
- Fungistatic - converted to 5-fluorouracil, interfere with DNA/RNA synthesis (pyrimidine metabolism)
- Narrow: Yeast - Candida albicans & Cryptococcus
- Bone marrow suppression
- Loss of converting enzyme or transporters
- Oral, Penetrates CNS
*Often cotreat with Amphotericin B
(increase uptake, minimize potential resistance)
9
Q
Griseofulvin
- Class
- MOA
- Spectrum
- Toxicity
- Resistance
- Distribution
A
- Microtubule inhibitor
- Fungistatic - binds microtubules leading to multinucleate cells
- Dermatophytes
- Teratogenic
- change to beta-tubulin
- Lipids increase oral absorption, take with fat!
***Take for months because bacteria concentrates in dead keratinized skin.
10
Q
Caspofungin
- Class
- MOA
- Spectrum
- Toxicity
- Resistance
- Distribution
A
- Echinocandins
- Impairs beta-1,3 glucan synthesis, Fungicidal: against Candida albicans, Fungistatic: against Aspergillus
- Candida albicans, systemic
- hypersensitivity rxn: fever, rash
- change in 1,3-beta-D-glucan synthase gene
- IV, large MW prohibits CNS penetration
11
Q
Can fungi produce spores?
A
Yes
12
Q
Are fungi multicellular?
A
Yes & No
Depends on type
13
Q
Do fungi have a cell wall?
A
Yes, chitin
14
Q
Do fungi have mitochonria?
A
Yes
15
Q
What are single cell fungi called?
A
Yeast
(reproduce asexually via budding)