Anti-Eukaryote Therapies ✅ Flashcards
Why are some anti-fungals limited to topical application?
Due to their toxicity
What are the classes of anti-fungal agents?
- Polyenes
- Azoles
- Echinocandins
Give 2 examples of polyenes?
- Nystatin
- Amphotericin B
What is the mechanism of action of polyenes?
They bind to ergosterol in the fungal cell wall, causing lysis of the cell membrane and cell death
Are polyenes specifically toxic to fungi?
Some are toxic only to fungi, but others also cause toxicity in the host
Give a polyene which can cause toxicity in the host?
Amphotericin
How does amphotericin cause toxicity in the host?
It binds to cholesterol in the kidneys causing nephrotoxicity
How are the nephrotoxic effects of amphotericin reduced?
Lipid preparations
Are polyenes broad or narrow spectrum?
Broad
Give 3 examples of azoles
- Fluconazole
- Itraconazole
- Voriconazole
What is the mechanism of action of azoles?
Block the synthesis of ergosterol, leading to fungal cell wall dysfunction
What is fluconazole used to treat?
Candida infections
What is voriconazole used to treat?
Conditions where activity against Aspergillus is required
Give 2 examples of echinocandins?
- Caspofungin
- Micafungin
What is the mechanism of action of echinocandins?
They inhibit an enzyme responsible for beta-glucan synthesis and prevent fungal wall synthesis, leading to cell death
What organisms are echinocandins active against?
- Candida
- Aspergillus
Are anti-fungal agents fungistatic or fungicidal?
Can be either
Give an example of a anti-fungal that varies if it is fungostatic or fungicidal depending on the organism
Voriconazole is fungicidal against Aspergillus, but fungostatic against Candida
What is the problem with the treatment of helminth infections?
Effective agents with anti-helminth activity are limited
Give 3 anti-helminth agents
- Mebendazole
- Albenazole
- Praziquantel
What is mebendazole used to treat?
Intestinal nematodes
What effect does mebendazole have on intestinal nematodes?
Causes immobilisation and death
Why is mebendazole only used for intestinal nematodes?
It is poorly absorbed so can only act locally
What is the difference between mebendazole and albenazole?
Albenazole is better absorbed
What is albenazole used to treat?
Blood and tissue nematodes
What is praziquantel used to treat?
- Cestodes
- Trematodes
What limits the use of anti-protozoal agents?
Geographical resistance
How is geographical resistance to anti-malarial agents managed?
Knowledge of malaria species and travel destination are essential for appropriate prescribing
