Fidaxomicin is primarily used as an antibiotic to treat infections caused by Clostridioides difficile, a bacterium that can lead to severe diarrhea and colitis. It is particularly effective in cases where the infection recurs after initial treatment with other antibiotics or in patients where other treatments have failed. The drug works by inhibiting RNA synthesis in the bacteria, thereby stopping their growth and spread. Fidaxomicin is favored in clinical settings due to its targeted action, which minimizes disruption to the normal gut flora compared to broader-spectrum antibiotics. This selective activity helps reduce the risk of secondary infections and promotes faster recovery in patients. Additionally, it is used to prevent recurrence in high-risk patients. It is typically administered orally, making it convenient for outpatient treatment.