Antifungals - pyrimidines and polyenes Flashcards
example of pyrimidine antifungal
5-fluorocytosine
how does 5-fluorocytosine work, 2 ways
- disruption of DNA synthesis
2. disruption of translation
what is 5-fluorocytosine active against
crytococcus neoformans and candida species + some moulds
is 5-fluorocytosine used on its own or as combo therapy? And why is it used this way?
combo with Amp or fluconazole. Less resistance experienced with combo therapy
What is 5-fluorocytosine used generally for?
treatment of systemic fungal infections and mainly for crypt. meningitis
What is the patient at risk of if 5-fluorocytosine is used for more than two weeks at >100mg/L?
Bone marrow supression
What toxicity does 5-fluorocytosine present?
liver toxicity
what does 5-fluorocytosine interact with?
Brivudine
2 Examples of polyene?
Nystatin and Amphotericin
Another name for Amphotericin
Ambiosome
What can Amphotericin be used for
most yeasts and moulds
Is Amphotericin broad or narrow spectrum?
Broad
How is 5-fluorocytosine given?
IV
How is Nystatin and Amphotericin given?
IV but occasionally given topically
What type of therapy can Amphotericin be used for?
Empiric therapy (based on past experience)
What toxicity do patients experience with Amphotericin
Nephrotoxicity
Are most yeasts sensitive to Nystatin?
yes
How is Nystatin given?
Topical
why is Nystatin given topically?
too toxic
What is Nystatin used to treat?
oral/vaginal candidosis