Evaluation of combination therapy for Clostridium difficile infection

Objectives: Current treatment guidelines recommend the use of metronidazole or oral vancomycin to treat Clostridium difficile infection in the majority of patients depending on the severity of symptoms. The primary objective of this study was to determine significant factors associated with the use of combination oral vancomycin and metronidazole as initial therapy for moderate to severe Clostridium difficile associated diarrhea at an academic medical center. The secondary objectives of this study were to evaluate the incidence of non-response, recurrence, relapse, and rate of complications by treatment and strain type (NAP1/B1/027). Methods: This retrospective medical record review has been approved by the Institutional Review Board. Adult patients with stool specimens tested for detection of Clostridium difficile toxin B by PCR between April 2010 and March 2011 at a tertiary care, academic medical center were evaluated. Patients were included in the study if diagnosed with moderate to severe disease and received either monotherapy with metronidazole, monotherapy with oral vancomycin, or combination therapy with metronidazole and oral vancomycin for at least 80% of the first 10 days of treatment. Patients who are discharged alive within 72 hours of admission or who received therapy for less than 48 hours were excluded. Data collected includes demographic information, Clostridium difficile PCR results and strain type, associated symptoms, prior antibiotic exposure, severity classification, and therapies prescribed. The rate of response will be compared between the three treatments using Chi Square. Results: All patients (N=411) with laboratory evidence of Clostridium difficile during the study time period have been evaluated and 56 patients received oral vancomycin along with metronidazole for at least 80% of the first 10 days of treatment. Conclusions: Data collection is complete and data analysis will be completed by the presentation date.