August 26, 2015 - Anti-Fungals Flashcards
Differences Between Human and Fungal Cells
Humans have cholesterol while fungus has ergosterol.
Fungus has chitin and glucan in their cell walls.
Types of Fungus
- Yeast - unicellular and reproduce by budding
- Mold - filamentous with specialized reproduction apparatus
- Dimorphic - either a yeast or a mold depending on the temperature of the surroundings. Often will be a yeast in the body at warm temperatures and a mold in the surroundings at cooler temperatures.
Common Types of Yeast
- Candida albicans*
- Candida “non”-albicans*
- Cryptococcus neoformans*
Common Types of Mold
- Aspergillus*
- Zygomycosis*
- Dermatophytes (tinia)*
Common Types of Dimorphic
Many of these are endemic to different regions.
Targets for Anti-Fungal Drugs
- Glucan synthetase inhibitors
- Cell membrane disruption / pore formation
- Ergosterol synthesis inhibitors
- DNA synthesis inhibitors
Echinocandins
All end in -FUNGIN
Active against ALL Candida
Mechanism is to target glucan synthesis
Polyenes
Amphotericin B (AmphoTerrible), Liposomal AmphoB, and Nystatin.
All target the cell membrane.
All very toxic in IV form.
Liposomal AmphoB is the first line treatment for Zygomycosis however (face melting disease with horrible prognosis).
Azoles
All end in -AZOLE
All target ergosterol synthesis
All have high oral bioavailability. PO = IV