Treating pneumonia with azithromycin is linked to lower risk of death but a slightly higher risk of myocardial infarction in older patients, according to a large retrospective cohort study.
Although azithromycin is recommended in combination with macrolides for the first-line treatment of patients hospitalized with pneumonia, recent research suggests it is associated with an increased risk of cardiovascular events. However, the current findings suggest that while it is associated with a slight increase in MI risk (number needed to harm equals 144), it is not associated with "any cardiac event," cardiac arrhythmia, or heart failure, and that the reduction in 90-day mortality risk (number needed to treat of 21) is large enough to provide an overall net benefit.
Dr. Eric M. Mortensen
Dr. Eric M. Mortensen of the Veterans Affairs North Texas Health Care system, Dallas, and his colleagues reported their findings in the June 4 issue of JAMA.
In the current study, 20 in 31,863 patients aged 65 years and older who were exposed to azithromycin were significantly lower than in an equal number of propensity-matched controls who were not exposed (17.4% vs. 22.3%; odds ratio, 0.73).
The risk of myocardial infarction, however, was significantly increased in the azithromycin group (5.1% vs. 4.4%; OR, 1.17), investigators reported.
Azithromycin use was defined as patients’ receipt of at least one dose of azithromycin during the first 48 hours after admission.
Study subjects were older adults with a mean age of 77.8 years in the national Department of Veterans Affairs administrative database who were hospitalized with pneumonia between 2002 and 2012 (JAMA 2014 June 4 [doi:10.1001/jama.2014.4304]). Most patients (98%) were male.
The study had a relatively small number of female subjects and relied "upon ICD-9 diagnosis of cardiovascular events rather than clinical information, which particularly may affect the diagnosis of heart failure,"h the authors said. However, they said, treating physicians were likely to have believed the patients in the study indeed had pneumonia and did not show any bias toward azithromycin.
This study was supported by a grant from the National Institute of Nursing Research. Dr. Mortensen reported having no disclosures. Other researchers reported receiving grants from industry sources.