Antifungals Flashcards
Antifungals that don’t work on the cell wall?
Griseofulvin and flucytosine
Systemic fungal infection DOC
amphotericin B
Amphotericin B (Fungizone) MOA
Interacts with ergosterol within the membrane to create a pore that leads increased permeability and to depolarization. Fungicidal.
Amphotericin B Toxicity
NEPHROTOXIC (slow renal excretion).
Amphotericin B infusion toxicity
immediate during infusion. Chills, fever, muscle spasm, vomiting, HA.
Flucytosine (ancobon) MOA
Enters the cell. Is converted into 5-fluorouracil and interrupts DNA and RNA synthesis. Conversion happens in fungal and bacterial cells.
Flucytosine kinetics
Oral. Enters the CSF.
Amphotericin B kinetics
Broad spectrum. IV. Poor CNS penetration.
Cryptococcus infections DOC
Flucytosine with amphotericin B
Flucytosine toxicity
renal, bone marrow depression (anemia, leukopenia, thrombocytopenia),hepatotoxicity.
Azoles (4)
ketoconazole, fluconazole, voriconazole, itraconazole
Azoles MOA
inhibit the production of ergosterol. Causes an accumulation of toxic intermediates and increases membrane permeability which inhibits fungal growth. Fungistatic.
Ketoconazole toxicity
Inhibits P450s (drug interactions), gynecomastia.
Fluconazole kinetics
oral/IV. Renal elimination. Penetrates the CSF.
Antifungals that penetrate the CSF?
Fluconazole and flucytosine.
Fluconazole toxicity
Less drug interactions than the others
Aspergillus DOC
Voriconazole with amphotericin B
Voriconazole toxicity
Metabolized by and inhibits P450s mainly CYP2C19 (A LOT of drug interactions), Visual impariment.
Itraconazole toxicity
potent inhibitor or CYP3A4
Echinocandins (3)
Caspofungin, Micafungin, Anidulafungin
Echinocandins MOA
inhibits sythesis of cell wall component called beta (1,3)-D-glucan which is not present in mammalian cells. “penicillin of antifungals” Fungicidal.
Caspofungin uses
treatment of invasive aspergillosis in refractory patients. Also for esophageal candidiasis.
Caspofungin toxicity
Less drug interactions!
Griseofulvin (fulvicin U/F) MOA
enters the cell and binds to the microtubules to destroy the mitotic spindle. Fungistatic. Binds to keratin to prevent new skin infections.
Onychomycosis DOC
Griseofulvin
Griseofulvin kinetics
used for dermatophytes. Oral only.
Griseofulvin toxicity
headache
Griseofulvin contraindications
acute intermittent porphyria, hepatocellular failure.
Terbinafine (lamisil) MOA
interferes with sterol sythesis. oral or topical.
Terbinafine use
effective against onychomycosis but not the DOC
Nystatin (myostatin) MOA
polyene antibiotic. Creates pores in the membrane similar to amphotericin B.
Nystatin Uses
oral or topical for candida infections.
Naftifine (Naftin)
OTC for athletes foot/jock itch
Tolnaftate (tinactin)
OTC for athletes foot/jock itch
Tioconazole (vagistat)
OTC azole
Miconazole (monistat)
OTC azole
Clotrimazole (Lotrimin)
OTC azole. Lozenge for candidal infections.