Fungal Flashcards
Which fungi are opportunistic?
Aspergillus and Candida Albicans
Which fungi cause systemic disease?
Coccidiodies
Histoplasmosis
Blastomycosis
Cryptococcus
What is the target of anti-fungals?
cell wall
ergosterol (a sterol unique to fungi)
What is MOA of Amphotericin B?
binds ergosterol and forms leaky pores in fungal membrane?
What is clinical application for Amphotericin B? What form is used for systemic infection?
IV form Opportunistic: Aspergillus, Candidemia : Systemic: Coccidiodies Histoplasmosis Blastomycosis Cryptococcus
What are ADE of amphotericin?
Nephrotoxicity
Infusion site rxn’s : fever, muscle spasms, chills, hypotension
What is MOA of flucytosine? What form is it given in?
interferes with RNA and DNA synthesis in fungi
Oral form given
What are the clinical applications of flucytosine?
Treats cryptococcus and chromoblastomycosis inflections
What are ADE of flucytosine?
Renal excretions
Myelosuppression
What is MOA for Azoles?
inhibit the P450 enzyme system in fungi to stop production of ergosterol
What is the disadvantage to using azoles?
If used long term can develop resistance
Which azole is used to treat aspergillosis?
Voriconazole
Which azole can cause visual disturbances and is a class D pregnancy?
Voriconazole
Which azoles are used to treat blastomycosis?
itraconazole and fluconazole
Which azole is used to treat mucormycosis?
posaconazole
How is dermatophytosis treated? mycosis?
topical or oral azoles
oral/parenteral azoles
T/F Most azoles undergo hepatic metabolism?
True
Which azole is eliminated in urine unchanged?
Fluconazole
What are ADE of azoles?
GI upset and rash
Why is ketaconazole rarely used?
inhibits hepatic and adrenal P450 dependent enzymes
what are the 4 ways of azole resistance
- mutation or upregulation of P450 enzymes-decreases binding of azoles
- increased efflux proteins pump that push the drug out the cell
- alteration to anti fungal drug proteins
- alteration to membrane sterols
- reduced permeability
What is MOA of echinocandins?
Caspofungin: prototype
work at the cell wall to stop production of B 1-3 glucan to causes apoptosis (disrupts cell wall synthesis)
What is the clinical application of echinocandins? What form is it given in?
Candida, Aspergillus, replaces amphotericin during febrile neutropenia
IV only
What is mode of elimination for echinocandins?
GI elimination, you adjust the dose if liver issues but not necessary for renal
