Azoles vs Echinocandins and polyenes
How to tell Azoles and Echinocandins and polyenes apart when a board question makes them look alike.
Azoles make less ergosterol; echinocandins weaken the wall; polyenes punch membrane pores by binding ergosterol.
Side by side
Ergosterol synthesis blockade through 14-alpha-demethylase inhibition, with hepatic and drug-interaction clues.
Echinocandins block fungal cell-wall beta-glucan; polyenes bind ergosterol directly and form membrane pores.
Azoles inhibit fungal cytochrome P450-dependent 14-alpha-demethylase, reducing ergosterol synthesis.
Echinocandins inhibit beta-1,3-glucan synthase; amphotericin B binds ergosterol and disrupts fungal membranes.
Fluconazole/voriconazole plus liver enzyme or interaction clue points azole.
Caspofungin/micafungin points echinocandin; amphotericin infusion chills plus nephrotoxicity points polyene.
The trap
Ergosterol appears in azoles and polyenes, but azoles block synthesis while polyenes bind it directly.
The repair move
For antifungals, name the fungal structure first: membrane synthesis, membrane binding, or cell wall.
Try a free question
CoreA patient with candidemia is treated with fluconazole. The drug inhibits fungal ergosterol synthesis through 14-alpha-demethylase and has important drug-interaction concerns. Which class best fits?
Show answer and explanation
Answer: A. Azole. Azoles inhibit fungal 14-alpha-demethylase, reducing ergosterol synthesis; hepatic toxicity and drug interactions are key clues.
Why the other choices are tempting
- B. Echinocandins inhibit beta-1,3-glucan cell-wall synthesis.
- C. Polyenes bind ergosterol and form membrane pores.
- D. Allylamines inhibit squalene epoxidase.
- E. Flucytosine is the antimetabolite antifungal clue.
Flashcards
Tap a card to flip it.
What is the fastest separator for Azoles vs Echinocandins and polyenes?
Azoles make less ergosterol; echinocandins weaken the wall; polyenes punch membrane pores by binding ergosterol.
What clue should make you choose Azoles?
Ergosterol synthesis blockade through 14-alpha-demethylase inhibition, with hepatic and drug-interaction clues.
Quick answers
What is the fastest way to tell Azoles from Echinocandins and polyenes?
Azoles make less ergosterol; echinocandins weaken the wall; polyenes punch membrane pores by binding ergosterol.
What is the key clue for Azoles?
Ergosterol synthesis blockade through 14-alpha-demethylase inhibition, with hepatic and drug-interaction clues.
What is the key clue for Echinocandins and polyenes?
Echinocandins block fungal cell-wall beta-glucan; polyenes bind ergosterol directly and form membrane pores.
What is the common trap with Azoles vs Echinocandins and polyenes?
Ergosterol appears in azoles and polyenes, but azoles block synthesis while polyenes bind it directly.