Fungal Infections Flashcards
What is candiasis?
Candida is always present but overgrowth when the immune system is compromised can cause yeast infections such as thrush.
What is ringworm?
Fungal infection that survives by feeding off keratin in the skin. Fungi from the Trichophyton family causing infections such as dandruff and athlete’s foot.
What is blastomycosis?
Affects lungs of mainly healthy young males. If left untreated it may spread to the bones, skin and heart and is usually fatal. Symptoms are similar to that of bacterial pneumonia but treating for this would make it worse.
Where are aspergillus spores most commonly found?
Ubiquitious in air, especially in farm buildings.
What are polyenes?
Antifungals with large numbers of OH groups and double bonds that make holes in the fungal membrane causing leaks.
What is amphotericin B?
A polyene produced naturally by Streptomyces nodosus.
How is amphotericin B administered?
Topically or IV
Toxic to kidneys
What is nystatin?
Polyene produced by Streptomyces noursei used topically in candida albican infections.
What is the mechanism of action of azoles?
Attack cytochrome P450 to prevent the formation of ergosterol from squalene.
What is ketoconazole? Why is it not used systemically?
An azole used topically due to liver toxicity.
What is fluconazole?
An azole taken orally due to good absorption at any pH.
What occurs with high does of fluconazole?
Inhibit androgen synthesis in men
What is itraconazole?
Broad spectrum azole that is active against aspergillus,
Which azole anti fungal is toxic to guinea pigs?
Itraconazole
What is voriconazole?
Newer azole anti fungal used in immunocompromised patients
