Flashcards in Antifungals Deck (17)
What are the 4 target types common to antifungals?
Membrane function, ergosterol synthesis, cell wall synthesis, and nucleic acid synthesis
What are the molecular targets of cell wall synthesis inhibitors (and their matching drugs)?
Lanosterol demethylase: topical clotrimazole and tolnaftate, systemic fluconazole and terbinafine
Glucan synthesis: systemic caspofungin
What is the major topical cell membrane inhibitor? Systemic?
What is the major nucleoside analog used as an antifungal?
Which topical drug class is broad spectrum? Narrow?
Imidazoles (clotrimazole): Candida and dermatophytes
Allylamines (tolnaftate): Dermatophytes only
Which allylamine is used systemically? Why?
Terbinafine for onchomycoses (nail infxn)
Memory tool: What are the two broad spectrum antifungal classes and how are they used, topically or systemically?
ImidAZOLES (topical) and triAZOLES (topical and systemic)
Which are more toxic imidazoles or triazoles?
Imidazoles - that's why they are topical
Triazole and allylamines side effects are centered in what organ?
Liver: hepatotoxicity and CYP inhibition
What two organisms are the primary clinical use for caspofungin?
Candida and aspergillus, especially when resistant
Which glucan synthesis inhibitor is less toxic than amphotericin B?
What is the best treatment for oral thrush?
Clotrimazole troches (lozenges) >> topical nystatin
Which two antifungals may be used in compination in the treatment of life threatening fungal infections in immunocompromised hosts?
Amphotericin B and flucytosine
When does amphotericin cause fever, chills, and hypotension?
During its infusion delivery
When does amphotericin cause decreased GFR, Mg/K wasting, RTA, and normocytic anemia?
After chronic use
Flucytosine is deaminated to 5-FU. Why is this not overly toxic to the human host?
the deamination is performed by cytosine deaminase, which is only present in fungi