Leuven, Belgium—A common antibiotic appears to reduce treatment failure in patients admitted to the hospital for acute exacerbation (AE) of chronic obstructive pulmonary disease (COPD).

A report on the randomized, controlled trial published online in the American Journal of Respiratory and Critical Care Medicine notes that a low dose of azithromycin, initiated in the hospital and continuing for 3 months after discharge, reduced treatment failure compared with standard-of-care treatment alone.

Belgian researchers from Katholieke Universiteit Leuven and University Hospitals Leuven defined treatment failure as the need to intensify treatment with systemic corticosteroids and/or antibiotics, transfer the patient to the ICU or readmit the patient to the hospital after discharge, and death from any cause.

Background information in the article recounts previous studies indicating that azithromycin prevents COPD AEs. Whether the antibiotic could also reduce the need to intensify care of patients hospitalized for an exacerbation or lower the risk of a future exacerbation remained unclear, however, according to the study team.

“We wanted to establish a new treatment option for acute exacerbations with hospitalization as current treatments are clearly insufficient,” explained senior author Wim Janssens, MD, PhD. “Equally important, we wanted to see whether continuing azithromycin for a relatively short time after leaving the hospital could interrupt the vicious cycle of relapse, even after treatment withdrawal.”

To do that, the researchers conducted an investigator-initiated, multicenter, randomized, double-blind, placebo-controlled trial of 301 patients hospitalized for a COPD AE.

Participants, who had a smoking history of 10 or more pack-years and one or more exacerbation in the previous year, were randomized within 48 hours of admission to azithromycin or placebo.

Azithromycin was administered at 500 mg/day for 3 days in addition to standardized acute treatment of systemic corticosteroids and antibiotics, and was subsequently continued for 3 months. Patients were followed up for 6 months thereafter.

The treatment failure rate within 3 months was 49% in the azithromycin group and 60% in the placebo group (hazard ratio [HR] = 0.73; 95%CI 0.53-1.01; P = .0526), according to the authors.

At the same time, the rates of treatment intensification, step-up in hospital care, and mortality were 47% versus 60% (P = .0272), 13% versus 28% (P = .0024), and 2% versus 4% (P = .5075), respectively. That meant patients receiving the antibiotic spent 24% fewer days in the hospital and 74% fewer days in the ICU than those receiving placebo treatment.

Benefits were more significant among nonsmokers, the study authors emphasized, with current smokers experiencing little or no benefit from low-dose azithromycin.

The study notes that clinical benefit ended 6 months after withdrawal, adding that prolonged treatment might be required.

Although the study could not prove statistical significance of its primary endpoint, “a positive message of the trial is that our strategy reduced hospital time, days in the ICU and recurrent exacerbations in the most severe COPD group,” Janssens pointed out, adding that a large phase IV study with hospital readmission as the primary endpoint would be necessary before broad implementation of the current study’s findings.

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