Azithromycin benefits older people admitted to hospital with pneumonia

A study of the use of azithromycin by older patients admitted to hospital with pneumonia found a reduced risk of mortality within three months, but a slightly increased risk of heart attack, JAMA reports^[1].

The study, led by Eric Mortensen, of the University of Texas Southwestern Medical Center, Dallas, concluded that azithromycin, a macrolide antibiotic, has a net benefit in this population.

The researchers used propensity scoring to match 31,863 patients aged 65 years or older who received azithromycin to treat pneumonia after being admitted to hospital and the same number who received other antibiotics.

Death within 90 days was significantly less likely in azithromycin users versus other patients (17.4% versus 22.3%; odds ratio 0.73; P<0.001). Conversely, the proportion of patients who experienced at least one heart attack was significantly higher in those who had used azithromycin, compared with those who had not, at 5.1% versus 4.4% (odds ratio 1.17; P<0.001).

Risk of any cardiac event, cardiac arrhythmias and heart failure did not differ between the two groups.

Mortensen’s team calculated that the number needed to treat with azithromycin was 21 to prevent one death within 90 days, compared with a number needed to harm of 144 for myocardial infarction.