EMBARGOED UNTIL: Tuesday, September 10, 4:45 PM MDT
(Session 38, Paper K-335)
Albert Einstein Coll. of Med., Bronx, NY, United States
In a study comparing the effectiveness of different dosing regimens of oral vancomycin for treatment of diarrhea associated with Clostridium difficile infection, researchers found oral vancomycin at doses of 125mg every six hours to be similarly effective compared to 250mg or higher every six hours. The finding of this study can potentially reduce the drug costs for treatment without compromising effectiveness.
This work, conducted by researchers at Montefiore Medical Center, an urban academic medical center located in New York City, will be presented at the 53rd Annual Interscience Conference on Antimicrobial Agents and Chemotherapy on September 10th 2013 in Denver, Colorado.
Clostridium difficile infection is an infection of the large bowel that can result in mild to severe symptoms ranging from stomach pain, severe cramping, profuse diarrhea, and in the most severe form, result in complications leading to death. While oral vancomycin is the treatment of choice for more severe form of the infection, the optimal treatment dose has not been established.
At Montefiore Medical Center, oral vancomycin was commonly prescribed at 250mg or higher every six hours prior to 2008. With the establishment of the Antimicrobial Stewardship Team (a group that facilitates the appropriate use of antibiotics) in 2008, oral vancomycin 125mg every 6 hours was recommended as the dose of choice for this infection. The rationale for this change was based on data demonstrating oral vancomycin at doses of 125mg produce drug concentrations in the large bowel far exceed those necessary to kill Clostridium difficile. With this major institutional change, the researchers wished to compare the treatment outcomes of diarrhea associated with Clostridium difficile infection using the different dosing regimens.
Patients hospitalized at Montefiore Medical Center between 2006 and 2010 who had a diagnosis of diarrhea associated Clostridium difficile infection and received at least 72 hours of oral vancomycin were included in the study. The medical records of eligible patients were reviewed for demographics, clinical and laboratory parameters (such as vital signs, episodes of diarrhea, and white blood cell counts) for resolution of infection, other antibiotics prescribed during treatment of Clostridium difficile infection, death during hospitalization, and hospital readmission within 30-day after discharge. The study was approved by the Institutional Review Board of Montefiore Medical Center for compliance of patient confidentiality.
A total of 300 patients were included in the study with 197 patients prescribed oral vancomycin 125mg every six hours (low-dose group) and 103 patients prescribed 250mg or higher every six hours (high-dose group). Among patients in the high-dose group, the majority received oral vancomycin 250mg every six hours. Patient characteristics such as age, gender, risk factors for and severity of Clostridium difficile infection, and concomitant antibiotic therapy before and after diagnosis of Clostridium difficile infection were similar between treatment groups. Similar proportions of patients were prescribed oral vancomycin as initial therapy between the low-dose (48%) and high-dose (57%) groups.
Clinical improvement assessed 72 hours after starting oral vancomycin therapy was seen in 85% and 86% of patients in the low- and high-dose groups, respectively. Similarly, rates of clinical improvement at end of therapy or time of hospital discharge were found to be comparable in the low-dose (93%) and high-dose (96%) groups. Other outcome parameters including total length of hospital stay; rates of death during hospitalization, 30-day readmissions due to all causes and to Clostridium difficile infection were found to be similar between treatment groups.
The results of the study suggest the efficacy of oral vancomycin at doses of 125mg every six hours was comparable to that of doses 250mg or higher every six hours for most cases of diarrhea associated with Clostridium difficile infection. Larger randomized controlled studies in the future can further validate the results of the current study.