Antifungals Flashcards
Amphotericin B mechanism
Fungicidal or static // Binds to cholesterol on cell membrane and creates leaks
Amphotericin B use and dangers
IV inj // systemic/deep mycosis // Nephrotoxic!
Ketoconazole mechanism
Fungcidal or static // Stops Cytochrome P450 synthesis of cell membrane
Ketoconazole uses and dangers
Oral med - lipophillic and needs acid for absorption // Systemic mycosis, dermatophytosis, and yeast infection // Slow onset of effect (10d) // Also stops CP450 liver metabolism and steroid syntheses // Teratogenic + Hepatotoxic
Itraconazole mechanism
Fungicidal or static // Higher affinity for fungal CP450 - stops synthesis of cell membrane // Keratin binding
Good in cats
Itraconazole uses and dangers
Oral med - lipophylic and needs acid absorbtion // Broad spectrum antifungal; nail bed infections; choice for sporotrichosis//
Gi upset, monitor for hepatotoxicity and vasculitis of extremeties (ear tips) // Expensive
Fluconazole mechanism
Fungicidal or static // Affinity for fungal CP450 - stops synthesis of cell membrane // Good in cats
Fluconazole uses and dangers
Oral med - well absorbed w/o food // Safest and can use in cats // Crosses BBB better than others - cryptococcal meningitis // Excreted unchanged in urine - check kidney function // Price fluctuations
Terbinafine mechanism
Fungicidal // Inhibition squalene epoxidase that causes cell death via squalene accumulation in membrane// No effects on CP450
Terbinafine uses and dangers
For dermatophytosis and malezzia (made for human skin problems) // long persistence in skin & fatty tissue
Griseofulvin mechanism
Fungistatic // Binds to fungal microtubules to inhibit mitosis and synthesis of proteins
Griseofulvin uses and dangers
Oral - lipophyllic // Phenobarb decreases absorption // Tx of dermatophytosis vs Microsporum, Epidermophyton, and Trichophyton – accumulates in sweat & keratin // Cat toxicities - bone marrow effects + Teratogenic
