title: Comparison of treatment outcomes with vancomycin alone versus combination therapy in severe Clostridium difficile infection.
abstract: BACKGROUND
  The recommended treatment for severe Clostridium difficile infection (CDI) is oral vancomycin alone. Combination therapy with metronidazole is only recommended in cases complicated by shock, ileus, or toxic megacolon. However, patients with severe infection are often treated with combination therapy despite a lack of data supporting this practice.
  
  
  OBJECTIVE
  To evaluate differences in outcomes for patients with severe CDI treated with oral vancomycin alone versus combination therapy.
  
  
  METHODS
  Medical records of 78 patients with severe CDI receiving either oral vancomycin alone or combination therapy for ≥ 72h were retrospectively reviewed. The primary outcome was time to clinical cure of CDI, defined as the first day of resolution of diarrhoea for ≥ 48h without development of a complication. Other endpoints included cure rates, complication rates, and recurrence rates.
  
  
  RESULTS
  There was no difference in the incidence of clinical cure between monotherapy and combination therapy (57.1% vs 65.1%, P = 0.49). Median time to clinical cure was 7.0 days for the monotherapy group and 8.0 days for combination therapy (P = 0.19). After adjustment for potential confounders, the hazard ratio of the time to clinical cure for combination therapy compared with monotherapy was 0.58 (P = 0.10). There was no difference in recurrence rate or rates of individual complications between groups; however, there was a significantly higher composite complication rate in the combination therapy group.
  
  
  CONCLUSIONS
  These data suggest that there is no difference in treatment outcomes between monotherapy and combination therapy for severe CDI.
authors.affiliation: Cleveland Clinic, Department of Pharmacy, Cleveland, OH, USA.
authors.forename: S N
authors.initials: SN
authors.lastname: Bass
authors.forename: S R
authors.initials: SR
authors.lastname: Bauer
authors.forename: E A
authors.initials: EA
authors.lastname: Neuner
authors.forename: S W
authors.initials: SW
authors.lastname: Lam
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D016360:Clostridioides difficile / Q000302:isolation & purification*; D003015:Clostridium Infections / Q000188:drug therapy* / Q000382:microbiology; D004359:Drug Therapy, Combination / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000008:administration & dosage*; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D014640:Vancomycin / Q000008:administration & dosage*; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D008795:Metronidazole; D014640:Vancomycin
keywords: Clostridium difficile; Combination therapy; Metronidazole; Vancomycin