Fidaxomicin

How it works

It inhibits bacterial RNA polymerase, giving a narrow spectrum targeted at C. difficile with minimal disruption of the normal gut flora.

Prescribing in practice

• It is associated with lower rates of recurrence than vancomycin in C. difficile infection, which is its main clinical advantage and informs its place in therapy.
• It acts locally in the gut with minimal systemic absorption, so systemic toxicity is limited.
• Use should follow local infection-control and antimicrobial stewardship guidance for C. difficile.

Monitoring

Monitor resolution of diarrhoea and stool frequency, hydration, and for recurrence after treatment.

Counselling the patient

• Complete the full course even if symptoms improve quickly.
• Report any return of diarrhoea after finishing treatment.
• Maintain good hand hygiene to limit spread of infection.

Evidence & guidelines

NICE recommends fidaxomicin for Clostridioides difficile infection, supported by trials showing reduced recurrence compared with vancomycin.