B3-046 Antifungal Chemotherapy Flashcards
mechanism flucytosine
inhibits DNA/RNA synthesis by converting flucytosine to 5-fluorouracil
used with amphotericin B for cryptococcus menigitis
flucytosine
**resistance develops rapidly with monotherapy
PK: flucytosine
orally effective, spreads to CNS
adverse effects: flucytosine
low toxicity as it is not activated in mammalian cells
mechanism: amphotericin B
binds to ergosterol, forms holes in plasma membrane
amphotericin B can be given _______ to CNS
intrathecal
amphotericin B is typically administered
IV
the 1/2 life of amphotericin B is _______
2 weeks
amphotericin B is used for
severe systemic mycoses
**use initially, then switch
adverse effects: amphotericin B
shake and bake
chills, fever, nausea, vomiting, headache
nystatin is _______ for systemic use
too toxic
treatment for oral candidiasis
nystatin
inhibitors of ergosterol synthesis are ________ catalyzed
fungal CYP
mechanism: terbinafine
inhibits squalene epoxidase (ergosterol synthesis)
mechanism: azoles
inhibit ergosterol synthesis by blocking fungal CYPs
adverse effects: ketoconazole
blocks adrenal steroidgenesis [gynecomastia]
inhibits CYP3A4
used as adjunct therapy for prostate cancer
ketoconazole
itraconazole is used for
histo, blasto, sporothrix
most widely used antifungal
fluconazole
fluconazole is administered
oral or IV
fluconazole is ________ for fungal CYPs
more selective
as the newest triazole, voriconazole has improved _______ and __________
bioavailability; less mammalian CYP inhibition
more effective than ampho B against invasive aspergillus
voriconazole
adverse effects: voriconazole
visual disturbances