Antifungals Flashcards
All fungi are ____ organisms
eukaryotic
2 types of fungal infections
systemic
superficial (cutaneous, subcutaneous)
Fungal infections are the __ most common nosocomial infection
4th
Patients at greatest risk for mycoses
- surgical intensive patients
- prosthetics
- immunosuppressed
Fungi use _____ for cell membrane
ergosterol
Squalene is converted to ______ by _______
lanosterol
squalene epoxidase
Lanosterol is converted to _______ and catalyzed by _____
ergosterol
CYP450 (14a-sterol demethylase)
Amphotericin B/nystatin MOA
bind ergosterol
disrupt membrane stability
- pores, leakage
500x greater affinity for ergosterol
Amphotericin B fungistatic or fungicidal?
both!
depends on concentration and fungal sensitivity
Amphotericin B use
- broad spectrum
- life threatening systemic mycoses
BBW amphotericin B
for proper use
Nystatin
swish and swallow
oral thrush
Adverse reactions of amp b/nystatin
- infusion related effects (cytokine storm)
- renal toxicity (proximal tube)
- hematologic toxicity (myelosuppression in anemia –> decreased erythropoietin secretion)
cytokine storm
fever
chills
rigors
hypotension
** pretreat with APAP
Flucytosine MOA
- Transported into fungal cells by cytosine permeate
- Converted to 5FU by cytosine deaminase
- 5FU converted to 5FdUMP and FUTP
Flucytosine fungistatic or fungicidal?
fungistatic
Flucytosine resistance
during mono therapy, so restricted use
- due to mutations of permeate and deaminase
Flucytosine use
- cryptococcal pneumonia and meningitis
- systemic candidiasis