Antifungals Flashcards
MOA of echinocandins
Inhibit synthesis of 1,3 beta-glucans for cell wall synthesis
Choice of echinocandins in hepatic impairment
Micafungin
Anidulafungin
Spectrum of activity for echinocandins
Mainly candida
Aspergilus less effective
Choice of anti fungal for CNS infections
Fluconazole
Voriconazole
5-flucytosine
With at least 60% CSF penetration. Others unreliable
MOA of systemic azoles
Inhibit lanosterol 14-alpha-demethylase, reduce synthesis of ergosterol and cell membrane
Systemic azole that requires renal dosing adjustment
Fluconazole (renal excretion as unchanged drug)
Voriconazle (to use PO route if CrCl <50 due to presence of cyclodextrin)
DDI for systemic azoles
2C19/2C9 inhibitor: fluconazole, voriconazole
PPI: Itraconazole, voriconazole, posaconazole
3A4 inhibitor: all
ADR of fluconazole
HA
Rash
QTc prolongation
ADR of itraconazole
Pseudoaldosteronism (HTN, low K, alkalosis)
Peripheral edema
Worsened HF
Peripheral neuropathy
QTc prolongation
ADR of voriconazole
Visual changes
Neurotoxicity
Photosensitivity
Alopecia
QTc prolongation
ADR of posaconazole
Pseudoaldosteronism
Peripheral edema
QTc prolongation
ADR of isavuconazole
HA
LFT derangement
Hypokalemia
peripheral edema
QTc shortening
Spectrum of activity for systemic azoles
- All: candida (Fluconazole does not cover Candida crusei, aspergillus (except Fluconazole)
- Voriconazole/posaconazole: additional fusarium, scedosporium
- Posaconazole: additional zygomycetes
Choice of therapy for invasive candidiasis
1st-line: echinocandins
2nd-line: fluconazole, voriconazole if non-critically ill
Duration of therapy: 14 days after 1st negative blood culture. May consider step down therapy from IV echinocandins to PO azoles in stable patients with negative repeat cultures
Choice of therapy for invasive candidiasis for neutropenic patients
Additional mould coverage with IV voriconazole BD x 2 doses, followed by PO BD
