Outcome of metronidazole therapy for Clostridium difficile disease and correlation with a scoring system

Objectives: To determine the response rate of Clostridium difficile disease (CDD) to treatment with metronidazole and assess a scoring system to predict response to treatment with metronidazole when applied at the time of CDD diagnosis. Methods: Retrospective review of patients with CDD who received primary treatment with metronidazole. We defined success as diarrhea resolution within 6 days of therapy. A CDD score was defined prospectively using variables suggested to correlate with disease severity. Results: Among 102 evaluable patients, 72 had a successful response (70.6%). Twenty-one of the remaining 30 patients eventually responded to metronidazole, but required longer treatment, leaving 9 'true failures'. The mean CDD score was higher among true failures (2.89 +/- 1.4) than among all metronidazole responders (0.77 +/- 1.0) (p < .0001). The score was greater than 2 in 67% of true failures and 2 or less in 94% of metronidazole responders. Leukocytosis and abnormal CT scan findings were individual factors associated with a higher risk of metronidazole failure. Conclusions: Only 71% of CDD patients responded to metronidazole within 6 days, but the overall response rate was 91%. A CDD score greater than 2 was associated with metronidazole failure in 6 of 9 true failures. The CDD score will require prospective validation. Published by Elsevier Ltd on behalf of The British Infection Society.