IDSE Review
Updated Evidence For Optimal Management of C. diff Infection
BY MARK H. WILCOX, MD, FRCPATH
E
vidence continues to accumulate on the increased relative efficacy of some therapies for Clostridioides difficile infection (CDI), especially with respect to the prevention of recurrent infection.
There are 4 agents approved for managing CDI: 2 older antibiotics, metronidazole and vancomycin, and 2 newer options, the antibiotic fidaxomicin (Dificid, Merck) and a newer monoclonal antibody against toxin B, 1 of the 2 major C. difficile toxins (bezlotoxumab [Zinplava, Merck]). Four additional agents are in phase 1 to 3 clinical trials. Bezlotoxumab is given along with one of the standard-of-care antibiotics to reduce the risk for CDI recurrence by augmenting the host endogenous antibody response against C. difficile toxin B. The antibiotics aim to stop C. difficile growth and, thus, toxin production. However, the other crucial issues are whether C. difficile persists in the gut as spores, with the potential to germinate once antibiotic administration has
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IDSE.NET
stopped, and the extent of microbiome disturbance that the CDI therapeutic causes on top of the existing dysbiosis. Together, these issues determine the effectiveness of the therapeutic to achieve clinical cure and prevent infection recrudescence (recurrent CDI). We know that metronidazole, until recently the most common option for treating CDI, is inferior to vancomycin (and almost certainly to fidaxomicin).1-3 Thus, guidelines increasingly advocate the use of vancomycin (or fidaxomicin) rather than metronidazole, especially for the treatment of non-mild cases of CDI.4 Notably, however, fidaxomicin and bezlotoxumab have been shown convincingly to reduce the risk for recurrent CDI by 40% to 50% compared with vancomycin alone.5-7 This review
