Studies Further Support Shorter Antibiotic Courses in Gram-Negative Bacteremia

A shorter course of antibiotic treatment (7-10 days) for uncomplicated gram-negative bloodstream infections, including treatment of urinary tract associated gram-negative bacteremia, appears to be as effective as long-course antibiotic treatment, according to 2 posters presented at IDWeek 2019, held October 2 to October 6, 2019 in Washington, DC.^1,2

The 2 single-center retrospective studies were conducted to evaluate the efficacy of using shorter antibiotic courses in the treatment of bacteremia. Go, et al¹ compared short (7 to 10 days) with long (11-20 days) course of antibiotics for uncomplicated gram-negative bacteremia. The researchers from the University of Kentucky in Lexington analyzed data from 466 patients (208 in short-course treatment; 258 in long-course treatment).

Although patients in the long-course group had more admissions to the intensive care unit (ICU) compared with the group in the short-course group (52.7% vs 43.3%, respectively; P =.0426), were older (age 57±16.7 vs 53±15.9 years, respectively; P =.0119), had a higher Charlsaon Comorbidity Index (5.7±3.6 vs 4.6±3.6, respectively; P =.0009), and had longer hospital stays (23.2±25.6 vs 15.8±17.5 days, respectively; P =.0002). There was no difference in 30-day mortality between the long-course group and the short-course group (3.9% vs 3.4%, respectively; P =.7701).

Findings for 30-day mortality were similar in the second study, which evaluated failure rates between short- (7-10 days) vs long- (>10 days) course treatment of urinary tract-associated gram-negative bacteremia.² Researchers from the University Health System in San Antonio, Texas, analyzed data from 207 patients who received an intravenous or a highly bioavailable oral agent for ≥7 days (45 in short-course treatment and 162 in long-course treatment).

At baseline, both treatment groups had similar comorbidities, ICU admission, and vasopressor initiation. There was no statistically significant difference in the primary composite endpoint (comprising both 30-day all-cause mortality and 90-day recurrence): 4.4% in short-course treatment vs 6.2% in long-course treatment (P =.66). In addition, there was no difference in secondary outcomes, which included 30-day readmission, 90-day mortality, resistance development within 90 days, and Clostridium difficile-associated diarrhea.

While generalizability to more complicated cases may be limited, findings from these 2 studies add to the body of medical literature and evidence that supports the use of shorter antibiotic durations in gram-negative bacteremia.

References

1. Go J, Cotner S, Burgess D, et al. Short versus long course of antibiotics for uncomplicated gram-negative bacteremia. Presented at: IDWeek 2019; October 2-6, 2019; Washington, DC. Poster 149.

2. Badwal J, Hand E, Lyons J, Traugott K. Urinary tract associated gram-negative bacteremia: Impact of treatment duration. Presented at: IDWeek 2019; October 2-6, 2019; Washington, DC. Poster 150.