Antifungal Therapy Flashcards
1
Q
Amphotericin B
mechanism
A
Amphotericin “tears” holes
- binds ergosterol
- forms membrane pores
- allows leakage of electrolytes
2
Q
Amphotericin B
clinical use
A
- serious, systemic mycoses
- Cryptococcus
- Blastomyces
- Coccidioides
- Histoplasma
- Candida
- Mucor
- intrathecally for fungal meningitis
- supplement K+ & M2+(altered renal tubule permeability)
3
Q
Amphotericin B
toxicity
A
- fever/chills (“shake & bake”)
- hypotension
- nephrotoxicity
- arrhythmias
- anemia
- IV phlebitis
- hydration decreases nephrotoxicity
- liposomal amphotericin decreases toxicity
4
Q
Nystatin
mechanism
A
- same as amphotericin B
- topical form
- too toxic for systemic use
5
Q
Nystatin
clinical use
A
- “swish & swallow” for oral candidiasis (thrush)
- topical for diaper rash or vaginal candidiasis
6
Q
Azoles
A
- fluconazole
- ketoconazole
- clotrimazole
- miconazole
- itraconazole
- voriconazole
7
Q
Azoles
mechanism
A
- inhibit fungal sterol (ergosterol) synthesis
- inhibit CYP450 enzyme that converts lanosterol to ergosterol
8
Q
Azoles
clinical use
A
- local & less serious systemic mycoses
- fluconazole - chronic suppression of cryptococcal meningitis in AIDS patients & candidal infections of all types
- itraconazole - Blastomyces, Coccidioides, Histoplasma
- clotrimazole & miconazole - topical fungal infections
9
Q
Azoles
toxicity
A
- testosterone synthesis inhibition
- gynecomastia (ketoconazole)
- liver dysfunction
- inhibits CYP450
10
Q
Flucytosine
mechanism
A
- inhibits DNA & RNA biosynthesis
- conversion to 5-FU by cytosine deaminase
11
Q
Flucytosine
clinical use
toxicity
A
- systemic fungal infections
- combination w/ amphotericin B
- bone marrow suppression
12
Q
Echinocandins
A
- caspofungin
- micafungin
- anidulafungin
13
Q
Echinocandins
mechanism
A
inhibits cell wall synthesis
inhibits synthesis of ß-glucan
14
Q
Echinocandins
clinical use
toxicity
A
- invasive aspergillosis, Candida
- GI upset, flushing (histamine release)
15
Q
Terbinafine
mechanism
A
inhibits the fungal enzyme squalene epoxidase