Hospitalized Adults: Gastrointestinal Infections: Clostridium difficile Disease


Doses provided in this table are for patients with normal renal and hepatic function. Click on drug link to go to dosing guidelines.  Some antimicrobials are restricted (ID-R).  Click on link for guidelines on obtaining authorization.


Common Pathogens

Drug(s) of First Choice


Clostridium difficile-associated diarrhea Clostridium difficile

Initial episode, mild to moderate disease

(WBC ≤15K and SCr less than 1.5 times premorbid level)

Vancomycin 125mg PO q6h x 10-14 days.  If unable to obtain at discharge, can complete course with Metronidazole 500mg po q8h

Initial episode, severe disease

(WBC >15k and/or 50% increase in SCr)

Vancomycin 125mg PO q6h x 10-14 days.

Initial episode, severe disease with complications

(Severe disease with hypotension, shock, ilios, and/or megacolon)

Vancomycin 500mg PO/NG q6h x 10-14 days


Metronidazole 500 mg IV q8h x 10-14 days


Vancomycin PR Rectal vancomycin should be considered in patients with ileus. It is given as 500 mg in 100 mL of 0.9% NaCl and instilled q6h (retain each dose for 1h)

First recurrence

Same therapy as initial episode, stratified by illness severity

First recurrence, special population (hematologic malignancy with >30 days expected neutropenia, recent HSCT, recent treatment for GVHD, solid organ transplant <3 months)

FidaxomicinID-R: UCSF SFGH  VASF 200mg PO BID x10 days

Second recurrence

Vancomycin with tapered or pulsed regimen


Consult ID, GI


Evaluate for fecal microbiota transplant

For full guidance, see document on Management of C. difficile Infection.

Discontinue or streamline concomitant antimicrobials if possible.

IV metronidazole alone is not indicated for treatment of C. difficile diarrhea.

IV metronidazole should only be used in combination with PO vancomycin in the ICU.

Recurrence in 5-30% of patients after first episode and 33-60% after second episode.

ID CONSULT recommended in patients with severe disease with complications or multiply recurrent disease, and for consideration of rectal vancomycin administration.