Antiparasitic and Antifungal Agents and Resistance Flashcards
(25 cards)
What are some challenges when treating systemic mycosis?
Patient already debilitated by primary disease
Fungal cells are eukaryotic like host cells
Low therapeutic indices
What are targets for antifungal drugs?
Cell wall
Cell membranes
Nuclear division
Nucleic acid synthesis
What are fungal cell walls made of?
Glucan and chitin
What are fungal cell membranes made of?
Ergosterol
How do polyenes work?
Bind ergosterol and form channels in the membrane
What is the most common polyene used against systemic mycosis?
Amphotericin B
What is used for candidiasis?
Nystatin (more toxic)
What inhibit ergosterol synthesis?
Azoles
How do azoles inhibit ergosterol synthesis?
Inhibit lanosterol demethylase
How is amphotericin B made less toxic?
By being made into liposomes
What drug is most affective against yeast DNA/RNA synthesis?
5-fluorocytosine (5-FC)
How does 5-FC work?
It takes the place of cytosine in DNA; deaminase turns it into 5-FU in RNA
What inhibits cell wall synthesis?
Echinocandins (caspofungin)
How do echinocandins work?
Inhibits synthesis of beta-glucan from glucose
What does griseofulvin bind?
Tubulin and keratin
What inhibits nuclear division?
Griseofulvin
Where is griseofulvin effective?
In fungi infections of the hair and nails due to it’s high affinity to keratin
What does Metronidazole target?
Anaerobic bacteria
What is the drug of choice against Clostridium difficile
Metronidazole
What are the two most common Benzimidazoles?
Mebendazole and albendazole
What are Benzimidazoles?
Broad-spectrum antihelminthic activity
What enzyme in folic acid metabolism is needed by all organisms?
Dihydrofolate reductase (DHFR)
What drug is used for inhibiting folic acid synthesis in Plasmodium?
Pyrimethamine
What drug is used for inhibiting folic acid synthesis in bacteria?
Trimethoprim (TMP)
