- Macrolide that inhibits RNA Polymerase, and in turn Protein synthesis, leading to Bacterial cell death
- Narrow spectrum Antibiotic (C. difficile, Staphylococcus, Enterococcus)
- Does not affect Gram Negative Bacteria including normal bowel flora
- Minimal systemic absorption when taken orally
- As with oral Vancomycin, oral Fidaxomicin primarily stays in the Gastrointestinal Tract
-
Clostridioides difficile (Clostridium difficile)
- Considered first-line as of 2021 (preferred over Vancomycin due to lower recurrence rates)
- First Episode
- Fidaxomicin 200 mg orally twice daily for 10 days (up to 14 days if delayed treatment response)
- Recurrence
- Start: 200 mg orally twice daily for 10 days (or 200 mg orally twice daily for 5 days)
- Next: 200 mg orally once every other day for 20 days
- No renal or hepatic dosing adjustment needed
-
Clostridioides difficile (Clostridium difficile)
- High efficacy (90% cure rate, similar to Vancomycin)
- Lower C. difficile recurrence rates than with Vancomycin
- Unknown effects in pregnancy but limited systemic absorption
- Very expensive as of 2022 ($250/dose or $3000 to $4300 for a 10 day course in Clostridium difficile)
- LoVecchio (2022) Crit Dec Emerg Med 36(9): 32