Authors: Rachel Coleby, Future Science Group
Researchers from the VA Salt Lake City Health Care System (UT, USA) and the University of Utah (USA), have recently published a study demonstrating a lower risk of all-cause 30-day mortality when Clostridium difficile infections (CDIs) are treated with vancomycin as opposed to metronidazole. The research group, led by Vanessa Stevens (University of Utah), conducted their study on patients who had mild to severe CDI between 2005 and 2012.
CDI is responsible for a large number of hospital-acquired infections and, even after treatment, has a recurrence rate of 15–50%. The bacteria produce two toxins (Toxin A and Toxin B) that irritate the intestinal lining and cause symptoms such as watery diarrhea, fever, loss of appetite, nausea, and abdominal pain and tenderness.
CDI is currently treated by either one of two antibiotics; vancomycin or metronidazole. However, lower cost and risk of vancomycin resistance in other infections has led to a bias toward metronidazole. It has previously been demonstrated that the two antibiotics are equivalent but, as Stevens concluded: “Our work and several other studies show that this isn’t always the case.”
The researchers utilized a retrospective, propensity-matched cohort study to analyze over 10,137 patients, who had confirmed CDI for the recurrence of infection and the rate of mortality. The two groups studied had either been treated with vancomycin or metronidazole. These groups were further separated into those with mild to moderate disease, and those with severe disease.
The team demonstrated no significant difference in the two treatments with regards to the rate of recurrence in any of the groups, or of mortality in the mild to moderate groups. However, they demonstrated that patients with severe CDI who received vancomycin had a lower risk of mortality (approximately 20%) than the patients who had received metronidazole.
The researchers suggest that vancomycin should be the antibiotic of choice for patients with CDI in the future. However, this should be carefully considered both from an economic and a resistance point of view, potentially limiting vancomycin’s use to severe CDI only. “The optimal way to move forward is to do decision analysis that allows us to weigh the pros and cons of the various treatment strategies,” concluded Stevens.
Source: Stevens VW, Nelson RE, Schwab-Daugherty EM, et al. Comparative effectiveness of vancomycin and metronidazole for the prevention of recurrence and death in patients with Clostridium difficile infection. JAMA Intern Med. doi:10.1001/jamainternmed.2016.9045 (2017) (Epub ahead of print); https://unews.utah.edu/routinely-prescribed-antibiotic-may-not-be-best-for-treating-severe-c-diff-infections/