More Research Needed to Assess Oral Vancomycin Prophylaxis for C Difficile Infections

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There have been only 12 unique studies evaluating this treatment for the primary and secondary prevention of CDI, with only 1 conducted prospectively.

Despite limited data, oral vancomycin prophylaxis has shown promise in preventing clostridiodes difficile infections (CDI).1

A team, led by Andrew Darkow, Campbell University College of Pharmacy & Health Sciences, evaluated the utility of oral vancomycin prophylaxis, while discussing clinical controversies and suggesting when this approach might be best considered.

Vancomycin and CDI

It is currently unknown whether oral vancomycin prophylaxis could be used to reduce the risk of CDI during systemic antibiotic exposure.

It is also unknown which patients benefit the most using this approach.

Current Research

There have been 12 unique studies published that evaluated the utility of oral vancomycin prophylaxis for primary and secondary prevent of CDI. Of these studies, only 1 was conducted prospectively, with the majority of studies showing clinical benefit or no significant harm when administering oral vancomycin prophylaxis.

There has been notable heterogeneity found in the published research, mainly differences in the patient population, time from initial CDI episode, and doses and durations of oral vancomycin prophylaxis.

Other studies have shown a significant impact on the host microbiota after oral vancomycin treatment.

“The mostly retrospective and heterogeneous nature of the currently available evidence makes it difficult to draw definitive conclusions as to when OVP should be utilized and who may benefit most from its use,” the authors wrote.

The Future

The investigators said the results suggest targeting a specific patient population for oral vancomycin prophylaxis.

“High-risk patient populations (elderly, immunocompromised, and those expected to have a prolonged hospitalization) who are receiving parenteral antibiotics may be reasonable to target for OVP,” the authors wrote.

There is also more research needed in this field.

The investigators suggested future large prospective studies are needed to confirm more definitive conclusions on the risk/benefit profile of oral vancomycin prophylaxis. They also suggested attention paid to the development of more predictive risk-prediction models to best target who might most benefit from this treatment regimen.

Risk and Vancomycin

A recent study did identify risks for patients treated with vancomycin, namely being younger than 50 years and having high vancomycin trough levels could be risk factors for drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome.

The case-control study was led by Kimberly G. Blumenthal, MD, MSc, of The Mongan Institute at Massachusetts General Hospital.

The results show patients who were less than 50-years-old were associated with a higher vancomycin DRESS syndrome risk (adjusted OR [aOR], 3.21; 95% CI, 1.33-7.78). Although hypertension was found to be inversely associated with DRESS syndrome (aOR, 0.45; 95% CI, 0.25-0.82), they found no comorbidities associated with increased risk of DRESS.

The investigators also noted that a vancomycin trough of over 25 μg/mL and 30 μg/mL did have an association with greater risk of DRESS (adjusted odds ratio [aOR], 2.32; 95% confidence interval [CI], 1.18-5.11 and aOR, 8.69; 95% CI, 3.39-22.27, respectively).


Darkow, A., Johnson, S., Walker, H. et al. When Should Oral Vancomycin Prophylaxis be Used to Prevent C. difficile Infection?. Curr Infect Dis Rep (2023).