Questions – Antifungals

Okay, let's have a question. The following medications act on the fungal cell wall except A) Flucytosine B) Ketoconazole C) Miconazole D) Nystatin and E) Amphotericin B Good you said Flucytosine. Which of the following drugs is a drug of choice for Crytococcus? A) Ketoconazole B) Fluconazole C) Miconazole D) Terbinafine and E) Griseofulvin Right, fluconazole. Now ketoconazole is a narrow spectrum antifungal agent with a significant number of side effects and adverse events. It's not available in parental form. And it's used in really mucocutaneous candidaisis and dermatophytes infections. Miconazole is an azole as well. It's used against skin infections. Terbinafine and griselfulvin are medications that prodominantly focus on the skin because they bind to the stratum corneum. If you remember where I had a picture of the stratum corneum before. Fluconazole is the drug of choice in crytococcal infections, in particular cryptococcal meningitis. It is also used for the secondary prevention of cryptococcal infections. Other drugs useful in cryptococcal infections are the broad spectrum agents like itraconazole and amphotericin B and the narrow spectrum agent flucytosine which is similar to fluconazole. Which of the following agents act by creating a pore in the cell wall? Flucytosine. Terbinafine. The polyenes Ketoconazole Indapamide. The polyenes, right. Flucytosine acts on the nucleus to inhibit nucleic acid synthesis. Terbinafine binds to the stratum corneum of the skin and attaches to fungal cells to inhibit squalene breakdown. The toxic squalene inhibits cellular function of fungal organisms. Ketoconazole acts through ergosterol to create defects in the cell wall. Indapamide though is a diuretic. This has nothing to do with fungus and is just thrown in there as an extra choice. Now the polyenes include amphotericin B and nystatin which create hydrophilic pores in the cell wall allowing the efflux of solutes from the cytoplasm....