Used primarily to treat Clostridioides difficile infection (CDI), fidaxomicin is a narrow-spectrum antibiotic that acts locally in the gastrointestinal tract. It inhibits bacterial RNA polymerase, effectively targeting C. difficile while sparing normal gut flora. This selective activity reduces the risk of recurrence compared to broader antibiotics. Fidaxomicin is especially beneficial in patients with severe CDI or those at high risk of relapse. It is administered orally and remains largely unabsorbed in the gut, maximizing its concentration at the site of infection. Due to its favorable safety profile and lower recurrence rates, it is considered a preferred option in managing CDI, particularly in healthcare settings.