From the Guidelines
The risk of Clostridioides difficile (C. diff) infection is both dose-dependent and related to the length of antibiotic treatment, with higher doses and longer courses increasing the risk of developing C. diff infection. The evidence suggests that the duration of antibiotic exposure is a critical factor in the development of C. diff infection, with the highest risk occurring during and in the first month after antibiotic exposure 1. Broad-spectrum antibiotics such as clindamycin, fluoroquinolones, third-generation cephalosporins, and carbapenems pose the highest risk, and even short courses of these high-risk antibiotics can significantly increase C. diff risk 1.
To minimize C. diff infection risk, clinicians should use the narrowest spectrum antibiotic effective for the infection, prescribe the lowest effective dose, and limit treatment duration to the shortest effective course, as recommended by the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA) 1. This approach helps preserve the normal gut microbiome, which provides colonization resistance against C. diff.
Some key points to consider when prescribing antibiotics to minimize C. diff risk include:
- Minimizing the frequency and duration of high-risk antibiotic therapy and the number of antibiotic agents prescribed 1
- Implementing an antibiotic stewardship program to ensure appropriate antibiotic selection, dosing, and duration 1
- Targeting antibiotics based on local epidemiology and C. difficile strains present, and considering restriction of fluoroquinolones, clindamycin, and cephalosporins (except for surgical antibiotic prophylaxis) 1
- Being aware that the disruption of the intestinal microbiota by antibiotics is long-lasting, and the risk of CDI increases both during therapy and in the 3-month period following cessation of therapy 1.
From the Research
C diff Risk Factors
- The risk of C diff infection is dose-related and higher with longer courses and combination therapy 2
- Cumulative antibiotic exposures appear to be associated with the risk of CDI, with dose-dependent increases in risk associated with increasing cumulative dose, number of antibiotics, and days of antibiotic exposure 3
- Longer antibiotic duration is associated with increased risk, with 10- and 14-day courses incurring 12% and 27% more risk compared to 7-day courses 4
Antibiotic Exposure and C diff Risk
- The risk of C diff infection increases with antibiotic duration, and there are wide disparities in risks associated with antibiotic courses used for similar indications 4
- The intensity of antibiotic therapy, as measured by the antibiotic spectrum index (ASI), is independently associated with hospital-associated CDI, with each additional unit increase in ASI per antibiotic day associated with 1.09 times the risk of HA-CDI 5
- Certain antibiotics, such as moxifloxacin, ciprofloxacin, and clindamycin, are associated with a higher risk of C diff infection compared to others, such as amoxicillin, nitrofurantoin, and cloxacillin 4