Antifungal chemotherapy Flashcards
Candida is always present but can overgrow when the patient is immunocompromised. True or false?
True
Candida is a bacteria that causes candidiasis. True or false?
False - yeast
What causes athlete’s foot?
Ringworm
Blastomycosis is a fungal infection. True or false?
True
Pneumocystic pneumonia is a bacterial infection. True or false?
False - fungal infection which closely resembles bacterial pneumonia
How does fungal disease happen?
Colonisation when fungal spores are inhaled
Fungi are prokaryotes. True or false?
False - eukaryotes
Fungi have cell walls, just like we do. True or false?
False - have cell walls, but we don’t
What do fungi have in their cell membranes instead of cholesterol?
Ergosterol
Cryptococcosis is a fungal infection. True or false?
True
What is the mechanism of action of amphotericin B?
Binds to ergosterol in the fungal cell membrane and the amphotericin:ergosterol complex seems to form pores in the membrane, causing it to leak
Amphotericin B can be used to treat systemic fungal infections. How is it administered?
IV
How does nystatin work and what is it used to treat?
Binds to ergosterol and is used to treat candida albicans infections of the skin
What is terbinafine’s mechanism of action?
Inhibits sqaulene epoxidase, a rate limiting step in ergosterol synthesis
What is CYP450 14-α-demethylase?
An enzyme involved in the conversion of squalene to ergosterol
How do azole antifungals work?
They inhibit CYP450 14-α-demethylase
Why can’t azoles and polyenes be given together?
Because polyene antifungals rely on sterol binding to function, whereas azoles inhibit the synthesis of ergosterol
Nystatin, amphotericin B and terbinafine are which type of antifungals?
Polyene antifungals
Ketoconazole is formulated as a shampoo to treat dandruff and as a cream for treatment of athlete’s foot. True or false?
True
Fluconazole can be taken orally as absorption is good at any pH. It is widely distributed around the body, including the brain. True or false?
True
Fluconazole is used to treat cryptococcal infections. True or false?
True
Itraconazole cannot be given orally. True or false?
False
How do echinocandins work?
Target 1,3-B glucan synthesis
How does griseofulvin work?
It interferes with microtubule assembly
Griseofulvin is administered topically. True or false?
False - administered orally
What is the MOA of flucytosine?
converted to 5-fluorouracil and DNA and RNA synthesis are inhibited
