Short-Course Azithromycin for Lower Respiratory Tract Infection in Adults: Is 3 Days Enough?

Azithromycin, a macrolide antibiotic, has been shown to be effective in community-acquired pneumonia (CAP). The long half-life of azithromycin allows for a shortened treatment course, whereas the drug level is sufficiently maintained in the blood. The objective of this study is to review the body of evidence on the efficacy and safety of azithromycin in CAP treatment given as a regimen of 500 mg daily for 3 days. An English-language literature search was completed through PubMed (1980–2019). Full-text studies conducted in humans to compare a 5-day azithromycin course with a 3-day azithromycin course or azithromycin with other antibiotics for CAP treatment were included. Although the standard recommended CAP treatment regimen of azithromycin is 1500 mg in a total dose divided for 5 days, the efficacy of 1500 mg in a total dose divided for 3 days has been shown to be as effective as the 5-day course and comparable to longer durations of clarithromycin or amoxicillin/clavulanate for CAP treatment in an outpatient setting. Meanwhile, the evidence is less supportive of the use of 3-day azithromycin in patients who require hospitalization. The risk of cardiac death is low and not greater than the risk with other antibiotics.