Pharm - Antifungal Agents Flashcards
Identify the triazoles
- fluconazole (Diflucan)
- itraconazole (Sporanox)
- voriconazole (Vfend)
- posaconazole (Noxafil)
- isavuconazole (Cresemba)
State the mechanism of action for the triazoles
- Work primarily by inhibiting the cytochrome P450-dependent enzyme lanosterol 14-alpha-demethylase
- This enzyme is necessary for the conversion of lanosterol to ergosterol, a vital component of the cellular membrane of fungi.
- Disruptions in the biosynthesis of ergosterol cause significant damage to the cell membrane by increasing its permeability, resulting in cell lysis and death.
Which azoles have the broadest spectrums? (2)
- posaconazole
- isavuconazole
The bioavailability of azoles is dependent on what?
dependent on the product
Which azoles need to be given on an empty stomach?
- itraconazole
- voriconizole
What is significant of the absorption of posaconazole?
- its absorption can be saturation
- this limits the amount that can be given in 1 day
- daily dose is limited to 800 mg daily
Which azole is a prodrug?
isavuconazole
Which azole has non-linear kinetics?
voriconazole
Which azole has an active metabolite?
itraconazole
Why do azoles have the potential for significant drug interactions?
- b/c they are either metabolized by the P450 system
- or they inhibit enzymes that metabolize other drugns
What are the ADRs that ALL azoles can cause?
- GI distress
- hepatotoxicity
Unique ADRs of itraconazole
- HTN
- heart failure
Unique ADRs of isavuconazole
- N/V/D
- HA
- shortened QT interval*
Neurologic ADRs of voriconazole
- Vision changes
- Photosensitivity rash
- Visual hallucinations
- Neurologic toxicity – confusion, agitation, myoclonic movements, auditory hallucinations
- Difficulty thinking
- Nephrotoxicity
Identify the azoles that require loading doses
- Voriconazole
- Posaconazole
- Isavuconazole
