The FDA has approved Vowst (Seres Therapeutics/Nestle HealthScience), an oral capsule containing live fecal microbiota spores, for prevention of additional recurrences of Clostridioides difficile infection (CDI) in adults. Vowst is the first orally administered microbiota-based treatment to be approved for this indication. A rectally-administered live fecal microbiota-based suspension (Rebyota) was approved in 2022 for the same indication. Neither product is approved for acute treatment of CDI.

Clostridioides (formerly Clostridium) difficile infection (CDI) is the most common infectious cause of healthcare-associated diarrhea in adults. Guidelines on management of CDI have recently been updated.

The FDA has approved vancomycin oral solution (Firvanq – Cutis Pharma) for treatment of Clostridium difficile-associated diarrhea and enterocolitis caused by Staphylococcus aureus, including methicillin-resistant strains (MRSA).

The FDA has approved the fully human monoclonal antibody bezlotoxumab (Zinplava – Merck) for use with antibacterial drug treatment to reduce recurrence of Clostridium difficile infection (CDI) in adults with CDI at high risk for recurrence. It is the first drug to be approved for this indication.

The text that follows reviews some common bacterial infections and their empiric treatment pending the results of culture and susceptibility testing. The recommendations made here are based on the results of susceptibility studies, clinical trials, and the opinions of Medical Letter reviewers. Tables 1 and 2 list the usual dosages of antibacterial drugs.

The FDA has approved fidaxomicin (Dificid – Optimer), a new oral macrolide antibiotic, for treatment of Clostridium difficile-associated diarrhea in patients ≥18 years old. The incidence and severity of C. difficile infection (CDI) have increased in recent years with the emergence of an epidemic hypervirulent strain (NAP1/B1/027), possibly related to widespread use of fluoroquinolones.