Targeted Prophylaxis Prior to Prostate Biopsy May Cut Antibiotic Use

Targeted prophylaxis based on rectal cultures is as effective as empirical prophylaxis at preventing sepsis in patients undergoing prostate biopsy, but avoids the use of multiple antibiotics, according to a new study.

Researchers led by Richard J. Szabo, MD, of the Southern Permanente Medical Group in Irvine, Calif., studied the outcomes of 5,355 prostate biopsy procedures performed from May 1, 2013 to April 30, 2014. Urologists used targeted prophylaxis (TP) in 1,802 procedures (34%) and empirical prophylaxis in 3,553 (66%). In the TP group, rectal cultures were obtained prior to biopsy. The antibiotic sensitivities of Escherichia coli were used to guide the selection of a single antibiotic for prophylaxis. Urologists using empirical prophylaxis continued the usual regimen of ciprofloxacin monotherapy, but sometimes added another prophylactic antibiotic.

Sepsis developed in 8 cases (0.44%) in the TP group and 20 cases (0.56%) in the empirical group,  a between-group difference that was not statistically significant, Dr. Szabo's group reported in The Journal of Urology (2015;194:397-402).

“Our study suggests that TP can reduce antibiotic use by exchanging ciprofloxacin rather than augmenting ciprofloxacin without subjecting the patient population to an increased risk of sepsis,” the researchers wrote.

Results also showed that the prevalence of ciprofloxacin-resistant E. coli based on rectal cultures was 25%. In 9 of the 5,355 biopsy cases, sepsis developed from ciprofloxacin-sensitive bacteria despite the use of ciprofloxacin prophylaxis. Possible reasons for this prophylaxis failure include noncompliance with taking the antibiotic as directed and decreased bioavailability due to impairment of ciprofloxacin absorption by concomitant intake of dairy products or antacids, according to the investigators.

The authors noted that the incidence of post-biopsy sepsis has been increasing. This has led to increased prophylactic use of multiple broad-spectrum antibiotics, which may accelerate the development of resistant bacteria, the researchers pointed out.

Dr. Szabo and his colleagues acknowledged some study limitations, including retrospective data collection and a control group in which various usual care practices were used.

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