title: Continuation of antibiotics is associated with failure of metronidazole for Clostridium difficile-associated diarrhea.
abstract: BACKGROUND
  Metronidazole is first-line therapy for C. difficile-associated diarrhea primarily because of its low cost relative to vancomycin. Currently, it is unknown which patients will fail metronidazole therapy. Our goal was to prospectively evaluate risk factors for metronidazole failure.
  
  
  METHODS
  Included patients had symptomatic C. difficile-associated diarrhea, either mild or severe. Once enrolled, detailed baseline data were gathered. All interviews were performed daily while the patient was in the hospital for up to 14 days. If discharged prior to 14 days, the patient received a follow-up phone call on day 5 and day 14. Enrolled patients were given a daily stool survey to complete.
  
  
  RESULTS
  We enrolled 27 patients with C. difficile-associated diarrhea. All patients (10 of 10) who had their offending antibiotic(s) discontinued had symptomatic resolution of diarrhea by day 14 of metronidazole treatment. Conversely, 59% (10 of 17) of patients who remained on antibiotics during treatment had symptomatic resolution by day 14 (P=0.02). The risk ratio for treatment failure was 2.0 (95% confidence interval, 1.29-3.10) in patients who remained on antibiotics. In our treatment group, there would be one additional metronidazole treatment success for every 2.4 patients who discontinued antibiotics.
  
  
  CONCLUSIONS
  Patients who remain on antibiotics while undergoing treatment of C. difficile-associated diarrhea have a high likelihood of treatment failure with metronidazole.
authors.affiliation: Section of Gastroenterology, Temple University Hospital, Philadelphia, PA 19140, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Modena
authors.forename: Satya
authors.initials: S
authors.lastname: Gollamudi
authors.forename: Frank
authors.initials: F
authors.lastname: Friedenberg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000890:Anti-Infective Agents / Q000009:adverse effects* / Q000627:therapeutic use*; D016009:Chi-Square Distribution; D016360:Clostridioides difficile; D003015:Clostridium Infections / Q000188:drug therapy*; D003967:Diarrhea / Q000188:drug therapy* / Q000382:microbiology*; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D008297:Male; D008795:Metronidazole / Q000627:therapeutic use*; D008875:Middle Aged; D011446:Prospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D017211:Treatment Failure
chemical_list: D000890:Anti-Infective Agents; D008795:Metronidazole