5-day antibiotic treatment viable in CAP patients with clinical stability

Antibiotic treatment may be done for 5 days, as opposed to at least 7 days, in hospitalized patients with community-acquired pneumonia (CAP) who had achieved clinical stability by day 3 to 5, suggests a study presented at ESCMID Global 2025.

“CAP is a major contributor to antibiotic use and therefore a critical target of antibiotic stewardship,” said lead author Dr Simone Bastrup Israelsen, Copenhagen University Hospital, Hvidovre, Denmark.

“Despite its prevalence, there’s limited evidence on the optimal duration of antibiotic treatment. However, there is a growing trend to challenge the traditional, longer, fixed-duration approaches by exploring shorter courses that may reduce antimicrobial resistance and adverse effects,” she added.

In this multicentre, open-label, randomized, controlled noninferiority trial, Israelsen and her team enrolled adult patients hospitalized with radiologically confirmed CAP who had achieved clinical stability within 3 to 5 days. The criteria for clinical stability were as follows: blood pressure ≥100 mm Hg, heart rate ≤100/min, respiratory rate ≤24/min, oxygen saturation ≥90 percent, and temperature ≤37.8 °C.

Patients with immunosuppression, extrapulmonary infection, complicated pneumonia, and intensive care unit admission were excluded. All-cause death by 90 days of admission, the primary outcome, was assessed using the absolute risk difference with a 6-percentage-point noninferiority margin. Readmissions and adverse events (AEs) served as the secondary outcomes.

A total of 395 patients from six hospitals met the eligibility criteria and were randomized 1:1 to the intervention (shorter duration; n=198) or control (standard duration; n=197) group. Two participants withdrew their consent prior to initiation of the intervention, leaving 393 patients in the intention-to-treat (ITT) population. Of the remaining participants, 303 were included in the per-protocol analysis.

The baseline characteristics were similar between groups. Participants had a median age of 75 years, and 212 (54 percent) were female. The median duration of antibiotic treatment was 5.0 days in the intervention group and 7.1 days in the control group. [ESCMID 2025, abstract L0024]

Noninferiority

In the ITT population, six patients (3.1 percent) assigned to antibiotics for 5 days and four (2.0 percent) patients assigned to antibiotics ≥7 days died within 90 days (risk difference [RD], 1.1 percent, 95 percent confidence interval [CI], ‒2.0 to 4.1). This finding showed the noninferiority of the shorter treatment.

Likewise, the per-protocol analysis revealed that shorter antibiotic duration was noninferior to the standard duration (1.5 percent vs 1.7 percent; RD, ‒0.1 percent, 95 percent CI, ‒3.0 to 2.8).

The 90-day readmission rates did not differ significantly between the intervention and control groups (23.5 percent vs 21.3 percent; RD, 2.2 percent, 95 percent CI, ‒6.1 to 10.5).

Regarding safety, treatment-related AEs occurred in 14.8 percent of patients in the intervention group and 16.2 percent of those in the control group (RD, ‒1.4, 95 percent CI, ‒8.4 to 5.6). Serious AEs were also similar between groups (25.0 percent vs 24.9 percent; RD, 0.2 percent, 95 percent CI, ‒8.4 to 8.8).

“Antibiotic treatment for 5 days was noninferior to treatment for at least 7 days in patients hospitalized with CAP who had achieved clinical stability by day 3 to 5,” Israelsen said.

“These findings support shorter duration of antibiotic treatment as a safe and effective strategy when guided by clinical stability,” she added.