Table 2.

Recommended Treatment Options for the First Episode of CDI^a

Recommended Therapy	Dose/Schedule	Comment(s)
Metronidazole	Mild CDI: 500 mg 3 times daily for 10 days (PO or IV)	Less effective than other options for treating CDI Only used in the mildest cases and only via IV route if the patient is unable to take oral medications
Vancomycin	Mild to severe cases: 125 mg 4 times daily for 10-14 days PO	Superior to metronidazole for moderate to severe CDI Increases the risk of VRE89
	Severe complicated cases: 250-500 mg 4 times daily. Consider 500 mg of vancomycin in 100 mg normal saline per rectum every 6 hours as a retention enema in the face of ileus.
Fidaxomicin	All forms of CDI: 200 mg PO twice daily for 10 days	Lower rate of recurrence than other treatments Less likely than vancomycin to promote acquisition of VRE25 More expensive than other treatments
Tigecycline	Refractory cases of CDI: 100 mg IV, then 50 mg IV twice daily	Not approved for treatment Can be used as rescue treatment for patients with severe CDI when treatment with vancomycin and metronidazole fails29
Nitazoxanide	All forms of CDI: 500 mg PO twice daily for 10 days	Not approved for treatment In preliminary study, as effective as metronidazole or vancomycin31,32 More studies are needed.
Rifaximin	All forms of CDI: 400-550 mg twice daily for 14 days	Not approved for treatment Has been used with tigecycline with or without vancomycin for refractory cases of CDI36,37 More studies are needed.
Colonic surgery (colectomy or colon bypass)	Indicated with shock, respiratory failure, lactate levels >5 mmol/L, signs of end organ damage. Associated with refractory CDI and fulminant colitis.	Colon-sparing approach has been described in the literature to reduce mortality and preserve the colon.

^aInitial antibiotics causing CDI should be stopped if possible, and patients should be hydrated.

CDI, Clostridium difficile infection; IV, intravenous; PO, oral; VRE, vancomycin-resistant enterococci.