Diarrhoea – Clostridioides difficile

Formerly known as Clostridium difficile.
Most cases of antimicrobial-associated diarrhoea are due to osmotic mechanisms and a pathogen will not be identified.
C. difficile is the causative organism in a very small proportion of cases but is nearly always involved when colitis occurs with antimicrobial-associated diarrhoea. Refer to acute diarrhoea in Hospital HealthPathways.

Drug Treatment

See separate recommendations for treating initial episodes (mild, moderate, and severe disease) and recurrence below.
Duration: 10 to 14 days.

Initial episode

Mild

If mild (normal WBC, < 3 bowel motions per day) with no systemic upset it may be sufficient to discontinue antimicrobials.
If antimicrobials must continue, treat as for “Moderate” and consult with Infectious Diseases.

Moderate

If IV therapy is required because patient is nil by mouth, use metronidazole IV 500 mg every eight hours. Vancomycin IV should not be used as it is not effective for C. difficile due to inadequate penetration into the colon.

metronidazole

HML Sched NZF PML noids

PO 400 mg three times a day

Metabolised by unknown pathways. (fe = 0.1).

If metronidazole fails

vancomycin

HML Sched NZF PML noids

PO 125 mg four times a day (use IV formulation orally or pharmacy can compound a liquid)

Severe

Any of the following: WBC > 15x10⁹/L, Temp > 38.5°C or < 35°C, acutely increased plasma creatinine concentrations (e.g. > 50% increase from baseline), evidence of severe colitis – consult with Infectious Diseases.
If IV therapy is required because patient is nil by mouth, use metronidazole IV 500 mg every eight hours. Vancomycin IV should not be used as it is not effective for C. difficile due to inadequate penetration into the colon.

vancomycin

HML Sched NZF PML noids

PO 125 mg four times a day (use IV formulation orally or pharmacy can compound a liquid)

Recurrence

The relapse rate for C. difficile is 20% with treatment as spores persist in the GI tract. Recurrence, defined as clinical symptoms plus isolation of C. difficile within 2–8 weeks of initial symptom resolution, does not represent resistance. Treat with a tapering vancomycin dose as below and consult with Infectious Diseases.

vancomycin

HML Sched NZF PML noids

PO 125 mg four times a day for 2 weeks, then 125 mg twice daily for 1 week, then 125 mg once daily for 1 week, then 125 mg every second day for 1 week, then 125 mg every three days for 1 week (use IV formulation orally or pharmacy can compound a liquid)

Topic Code: 99234