Antifungals

Question 1

Clomitrazole

Answer 1

inhibits 14-α demethylase

• prevents conversion of lanoesterol -> ergosterol
• increased membrane permeability

other actions incl. inhibiting:

1) The endogenous respiration
2) The transformation of yeasts to mycelial forms
3) Triglyceride and/or phospholipid biosynthesis
4) Movement of Ca2+ and K+ ions across the cell membrane by blocking the ion transport pathway known as the Gardos channel

Question 2

General mechanism of -azoles

Answer 2

inhibits 14-α demethylase

• prevents conversion of lanoesterol -> ergosterol
• increased membrane permeability

Question 3

2 examples of azole antifungals:

Answer 3

Clotrimazole

Fluconazole

Question 4

2 examples of azole antifungals:

Answer 4

Clotrimazole

Fluconazole

Question 5

MoA of Ionophores

Answer 5

binds ergosterol -> forms pores => K+ leakage -> death

Question 6

2 examples of ionophores

Answer 6

Nystatin - Candida albicans, C. parapsilosis, C. tropicalis, C. guilliermondi, C. pseudotropicalis, C. krusei, Torulopsis glabrata, Tricophyton rubrum, T. mentagrophytes

Amphotericin B - Histoplasma capsulatum, Coccidioides immitis, Candida species, Blastomyces dermatitidis, Rhodotorula, Cryptococcus neoformans, Sporothrix schenckii, Mucor mucedo, and Aspergillus fumigatus

Question 7

Mechanism of Echinocandin antifungals

Answer 7

inhibits glucan synthase → causes inhibition of 1,3-β-D-glucan formation (essential component of fungal cell walls) ⇒ osmotic instability + cell death

Question 8

Example of echinocandin antifungal

Answer 8

Anidulafungin

Question 9

Echinocandin antifungals are only active against:

Answer 9

Candida and Aspergillus species

Question 10

Example of imidazole antifungal

Answer 10

Clomitrazole

Question 11

Example of triazole antifungal

Answer 11

Fluconazole