For Severe C. Difficile Infection, Oral Vancomycin Formulations Do Not Impact Outcomes

SAN DIEGO, CA— Vancomycin capsules and compounded oral solution do not differ in terms of patient outcomes in the treatment of severe C. difficile infection, according to a retrospective study presented at IDWeek 2012.

The first-line therapy for severe C. difficile infection is oral vancomycin. As vancomycin capsules can be considerably expensive, hospitals often compound oral solution from injectable powder as a less-expensive therapeutic option.

A retrospective, non-interventional cohort study of data from July 2006–July 2011 was conducted by Elizabeth A. Neuner, PharmD, BCPS, from the Cleveland Clinic, Cleveland, OH. Inclusion criteria consisted of age >18 years, positive C. difficile toxin or PCR, diarrhea (≥3 unformed stools/day), severe disease (white blood cells ≥15 and/or creatinine ≥1.5 times premorbid level) and having received oral vancomycin for ≥72 hours. Exclusion criteria consisted of recurrent C. difficile infection, severe complicated disease (ileus, shock, megacolon), or comorbidities affecting stool output at the commencement of vancomycin therapy.

The study's primary outcome was to compare the incidence of clinical cure at Day 10. Clinical cure was defined as resolution of diarrhea without development of complications (e.g., ileus, megacolon, colonic perforation, or colectomy) based on formulation.

A total of 76 patients were enrolled. Twenty-five (33%) patients received oral solution and 51 (67%) received capsules. Sixteen (64%) solution-treated patients and 26 (51%) capsule-treated patients received concomitant metronidazole therapy (P=0.283).

No significant differences in Charleston Co-morbidity Index, SOFA score, white blood cell count on admission, or number of stools on Day 1 of therapy existed between groups. Lactate was significantly higher in the solution group (median 1.5mmol/L [interquartile range 0.9–2.05] vs. 0.6mmol/L [interquartile range 0–1.2], P<0.001).

In regards to clinical cure rate at Day 10, there was no difference between the groups (64% vs. 59%, P=0.664). No significant difference was seen in 30 day mortality (20% for solution vs. 12% for capsules, P=0.338), recurrence within 30 days (4% for solution vs. 4% for capsules, P=1), or development of complications between groups. Additionally, Dr. Neuner's team noted there was no difference between groups in days to clinical cure through a time-to-event analysis (P=0.597).