Antibiotics for Colitis Treatment

Clostridium difficile-Associated Colitis

The European Society of Clinical Microbiology and Infectious Diseases recommends metronidazole 500 mg three times daily orally for 10 days for non-severe CDI, and vancomycin 125 mg four times daily orally for 10 days for severe CDI 1
Non-severe CDI is characterized by stool frequency <4 times daily, no signs of severe colitis, and white blood cell count <15 × 10^9/L, while severe CDI is characterized by fever, rigors, hemodynamic instability, peritonitis, ileus, marked leukocytosis (>15 × 10^9/L), elevated serum creatinine or lactate, and pseudomembranous colitis on endoscopy 1
For recurrent CDI (second episode or later), vancomycin 125 mg four times daily orally for at least 10 days, with consideration of taper/pulse strategy, is recommended 1
If oral therapy is impossible, metronidazole 500 mg three times daily intravenously plus intracolonic vancomycin 500 mg in 100 mL normal saline every 4-12 hours can be used 1
Teicoplanin 100 mg twice daily can replace oral vancomycin if available 1
Antiperistaltic agents and opiates should be avoided in patients with C. difficile colitis 1
Discontinuation of the inciting antibiotic is recommended if possible 1
Colectomy should be considered for perforation, systemic inflammation not responding to antibiotics, toxic megacolon, or severe ileus 1

The British Society of Gastroenterology recommends that antibiotics are not first-line therapy for ulcerative colitis 4

The treatment algorithm for colitis involves determining if colitis is infectious (particularly C. difficile) or inflammatory (IBD), and treating accordingly with metronidazole or vancomycin for C. difficile colitis 1, 2