Flashcards in Anti-fungals Deck (22)
Which drugs inhibit ergosterol synthesis?
Which drugs treat onychomycosis?
fluconazole, itraconazole, terbinafine
Which drugs inhibit cyt P450?
azoles, esp ketoconazole
Which drugs cause liver dysfunction?
Describe the formation of ergosterol for fungal membranes.
Squalene-->lanosterol via squalene epoxidase
Describe the formation of nucleic acids in fungus.
What is the basic MOA of the following anti-fungals?
terbinafine-->inhibits squalene epoxidase
flucytosine-->inhibits DNA/RNA synthesis after becoming 5-FU
griseofulvin-->inhibits microtubule formation
amphotericin B-->forms holes in ergosterol membrane
nystatin-->forms holes in ergosterol membrane
What are the important things to know about amphotericin B?
binds ergosterol and forms holes in membrane
allows leakage of electrolytes
good for systemic mycosis, like cryptococcus meningitis
How can you help decrease the nephrotoxicity while taking amphotericin B?
taking w/ lipophilic version of amphotericin
What are the important things to know about nystatin?
forms holes in ergosterol membrane
VERY potent, so only approved for use topically
used for oral candida, vulvovaginitis, diaper rash
What are the important things to know about flucytosine?
flucytosine-->5-FU via cytosine deaminase
5-FU inhibits RNA/DNA synthesis
used w/ amphotericin B for cryptococcal meningitis
can cause bone marrow suppression
What do you need to know about the azoles?
inhibits synthesis of ergosterol
inhibit CYTp450-->can cause liver dysfunction and elevated liver enzymes
can mess w/ hormones-->ketoconazole: gynecomastia
What are the topical azoles?
What are the typical indications for fluconazole?
cryptococcal meningitis, candida
What are the usual indications for itraconazole?
blastomyces, coccidioides, histoplasma (dimorphic)
Which of the azoles can be used to treat aspergillus?
Which one of the azoles can be used for refractory fungi?
What are the important things to know about terbinafine?
inhibits squalene epoxidase, decreases ergosterol synthesis
What is good to know about echinocandins?
inhibits cell wall synthesis by inhibiting formation of beta glucan
**caspofungin, anidulafungin, micafungin
**can cause GI, flushing
What are the indications for caspofungin?
C-candida, ASP-aspergillosis Fungin
What's the deal with griseofulvin?
interferes w/ microtubule formation
goes to keratin-containing tissues, so it is good for skin infections and tinea