A 7-day antibiotic regimen for bloodstream infections is as effective as 14 days, with comparable 90-day mortality rates, according to a recent study. 

Researchers compared 7-day versus 14-day antibiotic regimens for hospitalized patients with bloodstream infections. The study, published in The New England Journal of Medicine, aimed to evaluate whether a shorter course of antibiotics was as effective as a traditional longer course in achieving comparable mortality rates while minimizing antibiotic exposure.

The trial enrolled 3,608 patients across 74 hospitals in seven countries, including 1,814 in the 7-day group and 1,794 in the 14-day group. Patients with Staphylococcus aureus bacteremia, severe immunosuppression, or infections requiring prolonged treatment were excluded. Antibiotic selection and dosing were at the discretion of treating physicians. The primary outcome was all-cause mortality at 90 days, with a noninferiority margin of 4 percentage points.

At 90 days, mortality was 14.5% in the 7-day group and 16.1% in the 14-day group (difference: -1.6 percentage points; 95.7% confidence interval [CI], -4.0 to 0.8), demonstrating the noninferiority of the shorter regimen. Per-protocol analysis confirmed these findings (difference: -2.0 percentage points; 95% CI, -4.5 to 0.6). Relapse of bacteremia was rare and similar between groups (difference: 0.4 percentage points; 95% CI, -0.6 to 1.4). Secondary outcomes, including intensive care unit mortality, Clostridioides difficile infections, and development of antimicrobial resistance, showed no significant differences.

Notably, patients in the 7-day group had a median of 19 antibiotic-free days by day 28, compared to 14 days in the 14-day group. Adherence to the assigned regimen was higher in the 14-day group; however, 23.1% of patients in the 7-day group received treatment beyond the intended duration.

The researchers concluded that a 7-day antibiotic course was noninferior to a 14-day course in reducing mortality among hospitalized patients with bloodstream infections. This approach may decrease antibiotic exposure and associated risks, supporting antimicrobial stewardship efforts. Further studies are recommended to refine treatment durations for specific pathogens and patient populations.

Full disclosures can be found in the published study.