What is the mechanism of action of fidaxomicin?

Prepare for the Antibacterials (ABX) Exam. Study with flashcards and multiple-choice questions, each question comes with hints and explanations. Get ready to ace your test!

Multiple Choice

What is the mechanism of action of fidaxomicin?

Fidaxomicin works by inhibiting transcription in Clostridioides difficile. It binds to the bacterial RNA polymerase and blocks the initiation of RNA synthesis, which reduces production of the toxins that drive disease and also limits bacterial replication. This explains its selective, gut-focused activity and why it tends to spare most of the normal gut flora, helping to lower recurrence. It does not target folate synthesis, which is the mechanism of drugs that disrupt folate pathways. It also does not bind the 30S ribosomal subunit to cause misreading, which is characteristic of aminoglycosides and related agents. And it does not inhibit cell wall synthesis by binding PBPs, the action you’d see with beta-lactam antibiotics.

Fidaxomicin works by inhibiting transcription in Clostridioides difficile. It binds to the bacterial RNA polymerase and blocks the initiation of RNA synthesis, which reduces production of the toxins that drive disease and also limits bacterial replication. This explains its selective, gut-focused activity and why it tends to spare most of the normal gut flora, helping to lower recurrence.

It does not target folate synthesis, which is the mechanism of drugs that disrupt folate pathways. It also does not bind the 30S ribosomal subunit to cause misreading, which is characteristic of aminoglycosides and related agents. And it does not inhibit cell wall synthesis by binding PBPs, the action you’d see with beta-lactam antibiotics.

More practice questions