Dificid (fidaxomicin)

Optimer Pharmaceuticals

Approval Status
Approved May 2011

Treatment for
Clostridium difficile-associated diarrhea

Gastrointestinal , Immune System

Dificid (fidaxomicin) is a narrow-spectrum macrocyclic antibiotic.

Dificid is specifically indicated in adults for treatment of Clostridium difficile-associated diarrhea. To reduce the development of drug-resistant bacteria and maintain the effectiveness of Dificid, it should be used only to treat infections that are proven or strongly suspected to be caused by Clostridium difficile.

Dificid is supplied as a tablet designed for oral administration. The recommended dose is one 200 mg tablet orally twice daily for 10 days with or without food.

FDA Approval
The FDA approval of Dificid was based on two randomized, double-blinded, non-inferiority trials. The trials were designed to demonstrate the efficacy of Dificid (200 mg twice daily for 10 days) compared to vancomycin (125 mg four times daily for 10 days) in adults with Clostridium difficile-associated diarrhea (CDAD). The primary efficacy endpoints were the clinical response rate at the end of therapy, based upon improvement in diarrhea or other associated symptoms, and sustained clinical response 25 days after the end of treatment. Both endpoints were reached in both trials, showing that Dificid is non-inferior to vancomycin. The clinical response rate for both trials was 88% in the Dificid arms and 86% and 87% in the vancomycin arms. The sustained clinical response was 70% and 72% in the Dificid arms and 57% in the vancomycin arms.

Adverse events associated with the use of Dificid may include, but are not limited to, the following:

  • nausea
  • vomiting
  • abdominal pain
  • gastrointestinal hemorrhage
  • anemia
  • neutropenia

Fidaxomicin is bactericidal against C. difficile in vitro, inhibiting RNA synthesis by RNA polymerases.

For additional information regarding Dificid or Clostridium difficile-associated diarrhea, please visit the Dificid web page.

Dificid (fidaxomicin) Drug Information

The Dificid (fidaxomicin) drug information shown above is licensed from Thomson CenterWatch. The information provided here is for general educational purposes only and does not constitute medical or pharmaceutical advice which should be sought from qualified medical and pharmaceutical advisers.

Scroll to top