Canterbury DHB

Diarrhoea – 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

• Relapse rate for C. difficile is 20% with treatment and does not represent resistance. Spores persist in the GI tract, therefore re-treat with same agent and consult with Infectious Diseases.
• Duration: 10 to 14 days.

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 HMLSchedNZFPMLnoids Metronidazole F: 1 Half life: 8 hours Elimination: oxidation, glucuronidation fe: 0.1

PO 400 mg three times a day

• Metabolised by unknown pathways. (fe = 0.1).

If metronidazole fails

vancomycin HMLSchedNZFPMLnoids Vancomycin F: n/a Half life: 6 hours Elimination: renal fe: 0.9 Additional points: TDM

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.

must be prescribed or recommended by a consultant.

Topic Code: 99234