417. Combination Therapy vs. Monotherapy for the Treatment of Nosocomial Clostridium difficile Infection (CDI)
Session: Poster Session: Hospital-acquired and Transplant Infections
Friday, October 30, 2009: 12:00 AM
Room: Poster Hall A
Background: Treatment of Clostridium difficile infection (CDI) has been an increasing challenge with oral metronidazole or vancomycin. Clinicians have anecdotally explored the role of dual therapy for CDI. The primary objective was to compare the efficacy of combination therapy (metronidazole plus vancomycin) vs. monotherapy (metronidazole or oral vancomycin alone) for the treatment of CDI. Secondary objectives were to compare the following at end of therapy (EOT): fever <38.5C, WBC <12,000, diarrhea resolution and mortality rate.
Methods: IRB approval was obtained for this retrospective cohort study conducted from 10/1/07-9/30/08. Inclusion criteria: positive C. difficile toxin for nosocomial CDI, treatment with metronidazole, vancomycin or a combination regimen. Exclusion criteria: Age < 18 years (yrs) or > 89 yrs, pregnancy, history of CDI < 12 months, no treatment with metronidazole or vancomycin, received treatment < 4 days.
Results: Of 229 patients with C. difficile, a total of 148 pts met full study criteria: For combination (n=41) vs. monotherapy (n=107) respectively, mean age 62.2 ± 16.4 yrs vs. 65.4 ± 16.7(p=0.3); male 61% vs. 52%(p=0.5); mean length of CDI therapy 18 ± 9.5 days vs. 12 ± 8.9 days(p<0.001); severe CDI 61% vs. 44%(p=0.1); pseudomembranous colitis 24% vs. 4%(p<0.001). At end of therapy, clinical cure rates were 39% for combination vs. 33% for monotherapy(p=0.4); clinical improvement was 46% vs. 58% (p=0.09); clinical failure was 15% vs. 9%(p=0.4). For combination and monotherapy respectively, clinical cure was 44% vs. 39% for mild to moderate CDI(p=0.92); 36% vs. 23% for severe CDI(p=0.39). For combination and monotherapy at EOT respectively, fever < 38.5C was noted in 98% vs. 94%(p=0.70); WBC<12,000 64% vs. 70%(p=0.001); diarrhea resolution 54% vs. 46%(p=0.50); mortality rate at EOT was 10% vs. 4%(p=0.1).
Conclusion: In comparing combination therapy vs. monotherapy we found no statistically significant difference in the rates of clinical cure, clinical improvement or clinical failure. Further study is warranted in a larger patient population.
Noreen Chan Tompkins, PharmD1, Cheryl Herbert, RN, CIC1, Molly McGraw, PharmD1, Andrew Sahud, MD1 and  M. A. McGraw, None..
N. H. Chan Tompkins, None..
C. Herbert, None..
A. Sahud, None., (1)Allegheny General Hospital, Pittsburgh, PA