Seven Days of Antibiotics Enough for Uncomplicated Bacteremia

Patients with uncomplicated gram-negative bacteremia respond just as well to a 7-day course of antibiotics as they do a 14-day regimen, according to a new study.

Seven days of antibiotic treatment is sufficient for patients with uncomplicated gram-negative bacteremia, according to the results of a new study published online December 11 in the journal Clinical Infectious Diseases.

“Shortening antibiotic duration is important for antimicrobial stewardship,” Dafna Yahav, MD, from the Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel, and colleagues reported. “Current treatment guidelines recommend a range of treatment duration from 7 to 14 days for bacteremia.”

Because gram-negative bacteremia is a significant cause of morbidity and mortality in hospitalized patients, clinicians need evidence-based guidance about the appropriate duration of use of antibiotics to manage these cases.

With this in mind, Dr. Yahav and colleagues conducted a randomized controlled trial to investigate whether a shorter course of antibiotics is appropriate for patients who have gram-negative bacteremia.

The trial “showed noninferiority of 7 days compared to 14 days of covering antibiotics for patients with uncomplicated gram-negative bacteremia.”

However, patients with bloodstream infections have typically been excluded from these studies, and so data to inform the duration of antibiotic therapy for this patient population are lacking.

The study took place at 3 academic health centers in Israel and Italy, enrolling 604 patients who were hospitalized with gram-negative bacteremia. Patients were randomized to receive either 7 days (N = 306) or 14 days (N = 208) of antibiotics.

The main source of bacteremia among all study patients was the urinary tract (N = 604, 68%) and the main pathogens were Enterobacteriaceae (N = 543, 89.9).

According to investigators, the primary outcome of mortality, clinical failure, readmissions, or extended hospitalization at 90 days occurred in 140 (45.8%) patients who received 7 days of antibiotics, and in 144 (48.3%) of those who received 14 days of treatment (risk difference [RD], -2.6%; 95% CI, -10.5% to 5.3%).

Similarly, no significant difference was found between the 2 groups for the duration of hospitalization, rates of super-infections, development of antibiotic resistance, or occurrence of adverse events (including Clostridium difficile infection).

However, patients in the 7-day treatment group did experience significantly fewer cumulative antibiotic days than those in the 14-day group experienced, the team concluded.

In an accompanying editorial, Nick Daneman, MD, and Robert A. Fowler, MD, both from the University of Toronto, Ontario, Canada, emphasized that the results of this study have helped to close an important evidence gap.

The findings “suggest that we are heading towards a paradigm shift in the recommended treatment durations for patients with bloodstream infection,” they conclude.

“Evidence-informed shortening durations of antibiotic treatment offers the best approach to a clinical cure of patients with bacteremia, while minimizing potential patient- and population-level harms of antimicrobial treatment,” they concluded.