Infectious Diseases - Antifungals Flashcards
Mechanism of echinocandins?
What are the names of the three we commonly use?
Inhibit beta-1-3-D-glucan (–>inhibits cell wall synthesis)
Caspofungin
Anidulafungin
Micafungin
Which echinocandin is best used in liver dysfunction?
Anidulafungin - bypasses the liver
No drug-drug interactions
Which echinocandin is best used in obese patients?
Micafungin
Common drug interactions with caspofungin?
(caspofungin = echinocandin which inhibits beta-1-3-D-glucan to inhibit cell wall synthesis)
- cyclosporin A
- tacrolimus
- antiretrovirals
- phenytoin
- carbamazepine
- rifampicin
Uses of echinocandins?
(ie caspofungin / anidulafungin / micafungin)
Invasive aspergillus
Invasive candidiasis
Oesophageal candidiasis alternative in HIV
In combo for severe mucormycosis
Side effects of echinocandins?
(ie caspofungin / anidulafungin / micafungin)
neutropenia
Phlebitis
GI symptoms
Headache
What is the mechanism of polyenes?
What ones do we commonly use?
Polyenes bind to plasma membrane sterols to increase permeability and increase potassium channels (–> lose intracellular K)
Conventional Amphotericin B
Lipid Formulations of Amphotericin B (ambisome and abelcet)
Uses of polyenes?
(ie Conventional Amphotericin B, ambisome and abelcet)
Asperigillosis in haem patients allergic to voriconazole Alternative for invasive candidiasis Treatmetn fo zygomycosis and fusariosis Cryptococcal meningitis (1st line) Empiric antifungal therapy
Which polyene has best CNS penetration?
Lipid formulations of Amphotericin B = Ambisome
Dose adjustment with polyenes?
No dose adjustment needed in liver or renal failure or HDx
Side effects of polyenes?
(ie Conventional Amphotericin B, ambisome and abelcet)
Nephrotoxicity (higher mortality and length of stay if get AKI)
Infusion related side effects (ie hypotension and bronchospasm)
Mechanism of triazoles? Which ones do we commonly use?
Triazoles inhibit C14 alpha demethylase required for ergosterol synthesis for cell membrane
Voriconazole Fluconazole Itraconazole Posaconazole Isavuconazole
Which -azole is a substrate for CYP2C9 and CYP2C19?
Voriconazole
Uses of voriconazole?
Better affinity for aspergillus than fluconazole
Used also for fluconazole resistant candida
Uses of fluconazole?
Used for candida albicans
Also is an alternative at high dose for cryptococcal meningitis
