Antifungals Flashcards
Amphotericin B
Polyene antifungal that binds ergosterol in the fungal cell membrane and leads to pore formation and cell lysis.
Treats systemic mycoses (cryptococcus, blastomyces, coccidioides, histo, candida, mucor)
Supplement K and Mg due to altered renal tubule permeability
“Amphoterrible”: IV phlebitis, hypotension, nephrotoxicity, arrhytmias, anemia
Nystatin
Same MoA as amphotericin B (binds ergosterol in the fungal cell membrane and leads to pore formation and cell lysis).
Used topically because too toxic for systemic use. Treats oral candidiasis, diaper rash, vaginal candidiasis
Azoles
Antifungal that inhibits ergosterol synthesis by inhibiting P-450 enzyme (14-alpha-demethylase) that converts lanosterol to ergosterol.
Fluconazole treats all types of candida infections and is used as PPx of cryptococcal meningitis in AIDS patient.
Itraconazole treats Blasto, Cocci, Histo.
Clotrimazole/Miconazole treat topical fungal infections.
Toxicity: liver dysfuction (inhibits P-450), testosterone synthesis inhibition (ketoconazole)
Flucytosine
Inhibits DNA and RNA biosynthesis by conversion to 5-fluorouracil by cytosine deaminase.
Treats cryptococcal meningitis in combination with amphotericin B.
Toxicity: bone marrow suppression
Echinocandins (caspofungin, micafungin)
Inhibits cell wall synthesis by inhibiting synthesis of polysaccharide glucan, an essential component of fungal cell wall (unique in that in targets the fungal cell wall vs. the cell membrane)
Treats Candida and invasive aspergillosis
Terbinafine
Inhibits fungal enzyme squalene epoxidase, which results in decreased synthesis of ergosterol (present in cell membrane)
Treats dermatophytosis
Griseofulvin
Antifungal drug that binds microtubules and inhibits mitosis.
Deposits in keratin-containing tissues. Treats superficial oral infections and dermatophytes.
Toxicity: teratogenic, carcinogenic, increases P-450 and warfarin metabolism
