Fidaxomicin (brand name Dificid) is a narrow-spectrum, macrocyclic antibiotic primarily used to treat diarrhea caused by the bacterium Clostridioides difficile (C. diff) in adults and children at least 6 months of age.
It acts by inhibiting bacterial RNA polymerase, specifically blocking the initiation of transcription, which prevents the bacteria from growing.
Fidaxomicin is minimally absorbed into the bloodstream.
It remains concentrated in the gastrointestinal tract, where the infection is located.
Microbiome preservation:it has little impact on the favorable bacteria in the gut, which helps reduce the risk of the infection recurring.
Efficacy: Clinical trials have shown it to be as effective as oral vancomycin for initial cure but superior in preventing C. diff from coming back.
Standard Adult Dose: 200 mg taken orally twice daily (every 12 hours) for 10 days.
Available as 200 mg tablets or an oral suspension (liquid) for those unable to swallow pills.
Food: It can be taken with or without food.
Most Common Side Effects: Nausea, vomiting, abdominal pain, and constipation.
Precautions: Individuals with an allergy to other macrolide antibiotics should inform their doctor, as they may be at higher risk for an allergic reaction.