Using 'high risk' antibiotics increases C. diff rates three-fold

January 12th, 2015

The importance of antibiotic stewardship has been emphasized to save the dwindling efficacy of antibiotics, stave off a post-antibiotic era, and cut costs due to unnecessary drug use in the first few years of such programs. A compelling new incentive is being brought into the discussion -- can antibiotic stewardship programs temper the steady rise of epidemic Clostridium difficile infections (CDI)?

The Centers for Disease Control & Prevention reports that using antibiotics that a have a "high risk" of triggering C. diff led to three-fold increase risk of hospital-onset and post-discharge CDI. They compared patients exposed to certain antibiotics considered to pose a high-risk for subsequent development of CDI during their index hospitalization and subsequent hospitalizations, to patients without exposure to antibiotics. Specifically, the antibiotics classes considered to be high-risk were 3rd/4th generation cephalosporins, fluoroquinolones, and beta-lactam/beta-lactamase inhibitor combinations. In additional analyses, they compared patients with exposure to low-risk antibiotics (i.e., any antibiotic not included in the high-risk group) to patients without exposure to antibiotics.

They conducted a retrospective study of the relative risk of CDI in 2 large academic medical centers located in New York and Connecticut. The academic center in NY has approximately 700 beds and 40,000 discharges per year while the academic center in Connecticut has approximately 1,000 beds and 58,000 discharges per year. At the two hospitals, 35,567 index visits were observed with a total of 412 CDI cases (11.6 per 1,000 discharges). The risk of CDI among those exposed to high-risk antibiotics was 3 times higher compared to persons with low-risk or no antibiotic exposure.