For patients who fail to improve after 7 days or worsen with oral vancomycin discuss with an infection specialist (see How to get advice). Treatment will be dependent on clinical setting/severity of disease.
Antimicrobial recommendations:
Fidaxomicin 200mg every 12 hours orally
Duration = 10 days
OR
Vancomycin 500 mg every 6 hours orally
Duration = 10 days
PLUS
Metronidazole 500mg every 8 hours IV until improving or until 10 days has been completed