In an IDWeek 2023 Scientific Session titled Challenges in the Application of C. difficile Guidelines in Clinical Practice, Nasia Safdar, MD, PhD, professor, University of Wisconsin School of Medicine and Public Health, highlighted hurdles to exactly applying the updated 2021 ISDA C diff treatment guidelines. She also noted recent C diff product launches, including biotherapeutic medications.

“So now that you have made the decision to treat your patient who you believe to have true C diff infection [CDI],” she said, “the question is ‘What do you start treatment with?’ If only it was as simple as that.”

Dr. Safdar said there are a number of challenges that preclude healthcare practitioners from “doing exactly what the guidelines would like us to do.” Reviewing the 2021 Update to the IDSA Guidelines, she said the recommendation is to use fidaxomicin when treating a patient’s first CDI episode rather than a standard course of vancomycin (moderate certainly of evidence).

“This recommendation places a high value in the beneficial effects and safety of fidaxomicin, but its implementation depends on available resources.” When medication cost is a concern, vancomycin, she said, remains an acceptable alternative.

In patient with recurrent episodes of CDI, Dr. Safdar said the IDSA guidelines suggest fidaxomicin in a standard of extended-pulsed regimen rather than standard course of vancomycin (conditional recommendation, low certainty of evidence).

Vancomycin in a tapered and pulsed regimen or vancomycin as a standard course are acceptable alternatives for a first recurrence, the guidelines stipulate. “For patients with multiple C diff recurrences, vancomycin in a tapered and pulsed regimen, vancomycin followed by rifaximin, and fecal microbiota transplantation are options in addition to fidaxomicin.”

Dr. Safdar also surveyed several recent product launches, including bezlotoxumab, a human monoclonal antibody approved for the prevention of recurrent CDI in patients aged 18 years and older who are receiving concomitant standard of care antibiotic therapy for CDI and are at high risk for recurrence.

For patients with a recurrent CDI episode within the last 6 months, the ISDA guideline update recommends using bezlotoxumab as a cointervention along with standard of care antibiotics rather than standard of care antibiotics alone (conditional recommendation, very low certainty of evidence).

Other developments in drug development further shape treatment options. “The landscape is now of course different with the approval of VOWST and Rebyota (delivered by enema), both of which are live biotherapeutic products that have high efficacy for CDI from the standpoint of prevention of recurrence.”