Antifungals Flashcards
Classes of Antifungals
- Polyenes… Amphotericin B, Nistatin
- Azoles
- Echinocandins
- Allylamines
- Others
Amphotericin B:
- Class
- Mechanism
- Spectrum of Activity
- Mode of administration
Class: Polyenes
Mechanism: Binds to ergosterol in the fungal membrane, which increases permeability by forming spores!
Spectrum of Activity: Everything
Mode of Administration: IV
Nystatin:
- Class
- Mode of Administration
- Candida
Class: Polyenes
Mode of Administration: Topical, Oral, Intravaginal
Use: Candida
Azoles:
- Mechanism
Azoles: Itraconazole, posaconazole, fluconazole, voriconazole.
Mechanism: Inhibits synthesis of ergosterol in the fungal membraine… Fungus cell dies! Thus don’t use Azoles and Amphotericin B together! Both target ergosterol!
Treatment of choice (of azoles) for:
- Candida
- Aspergilus
- Mucor
- Candida = Fluconazole (relatively safe drug)
- Aspergillus = Voriconazole
- Mucor = Posaconazole (some activity)
- Mucor = Isavuconazole (VERY GOOD)
Adverse side effects of Voriconazole
- LOTS! Liver toxicity, lots of interactions! Hallucinations and inflammation!
Fluconazole
- Relatively safe
- Used for prophylaxis for surgery, neutropenia, and transplants
Voriconazole
Mode of Administration: Oral and IV, make sure to measure levels! If too high will make worse side effects!
Posaconazole
Used for preventing fungal infection
Echinocandins
Mechanism: Bind to glucan Synthase complex, inhibiting formation of fungi wall!
- Caspofungin, Anidulafungin, Micafungin
- Best and most effective for Candida for severe and invasive cases
- Little adverse side effects
Allylamines
- Ex. Terbinafine! (only one we need to know)
- Mechanism of action: Inhibit production of ergosterol by inhibiting enzyme which produces it. Fungal cell thus dies.
- Little side affects
Other Antifungals: 5-flucytosine:
- Mechanism
- Use
- Mechanism of action: Inhibits DNA synthesis
- Use: combine with Amphotericin B for treatment against cryptococcus (cryptococcal meningitis)
