00:00 Okay, let's have a question. 00:03 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. 00:23 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. 00:41 Now ketoconazole is a narrow spectrum antifungal agent with a significant number of side effects and adverse events. 00:47 It's not available in parental form. 00:50 And it's used in really mucocutaneous candidaisis and dermatophytes infections. 00:57 Miconazole is an azole as well. 00:59 It's used against skin infections. 01:02 Terbinafine and griselfulvin are medications that prodominantly focus on the skin because they bind to the stratum corneum. 01:09 If you remember where I had a picture of the stratum corneum before. 01:13 Fluconazole is the drug of choice in crytococcal infections, in particular cryptococcal meningitis. 01:19 It is also used for the secondary prevention of cryptococcal infections. 01:23 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. 01:37 Which of the following agents act by creating a pore in the cell wall? Flucytosine. 01:45 Terbinafine. 01:46 The polyenes Ketoconazole Indapamide. 01:53 The polyenes, right. 01:55 Flucytosine acts on the nucleus to inhibit nucleic acid synthesis. 02:01 Terbinafine binds to the stratum corneum of the skin and attaches to fungal cells to inhibit squalene breakdown. 02:09 The toxic squalene inhibits cellular function of fungal organisms. 02:13 Ketoconazole acts through ergosterol to create defects in the cell wall. 02:18 Indapamide though is a diuretic. 02:21 This has nothing to do with fungus and is just thrown in there as an extra choice. 02:27 Now the polyenes include amphotericin B and nystatin which create hydrophilic pores in the cell wall allowing the efflux of solutes from the cytoplasm. 02:37 And it also allows for toxic intermediates to develop through free radical formation inside the fungal cell wall. 02:44 That's it. 02:46 That's the fungal agents. 02:48 You did really well to sit through it. 02:51 You can go and write your exam and feel confident and show them what you know.
The lecture Questions – Antifungals by Pravin Shukle, MD is from the course Antimicrobial Pharmacology.
What is NOT useful in the management of cryptococcal infections?
Which pairing is correct?
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