https://immattersacp.org/weekly/archives/2012/05/22/5.htm

Azithromycin associated with more cardiac, all-cause mortality

Taking azithromycin can increase one's risk of cardiovascular death, especially for patients who have a high baseline risk of cardiovascular disease, a new study found.


Taking azithromycin can increase one's risk of cardiovascular death, especially for patients who have a high baseline risk of cardiovascular disease, a new study found.

The cohort study of Tennessee Medicaid patients was motivated by existing evidence that azithromycin is proarrhythmic. In the study, about 350,000 patients who took azithromycin were propensity-score matched with people who took no antibiotics (about 1.4 million control periods), 1.3 million patients who took amoxicillin, 265,000 taking ciprofloxacin and 194,000 on levofloxacin. The results were published in the May 17 New England Journal of Medicine.

The risk of cardiovascular death during five days of azithromycin therapy was almost three times that of patients taking no antibiotics (hazard ratio, 2.88; 95% CI, 1.79 to 4.63; P<0.001). Azithromycin patients also had an increased risk of death from any cause (hazard ratio, 1.85; 95% CI, 1.25 to 2.75; P=0.002). The increased risk of both cardiovascular and all-cause death was also found when the azithromycin patients were compared to the amoxicillin patients, who had no increase in risk compared to non-antibiotic-taking controls. The risk associated with azithromycin also exceeded that associated with ciprofloxacin but was similar to the risk from levofloxacin.

The study authors calculated that use of azithromycin could result in 47 additional cardiovascular deaths per 1 million courses of antibiotics. The danger for patients with high baseline cardiovascular risk is even greater: 245 cases per 1 million courses. Although a specific causal mechanism cannot be established, the data from this study support previous findings about potential adverse cardiac effects of azithromycin and levofloxacin, the authors concluded. They also noted that the increase in risk does not persist after azithromycin therapy ends.

In response to the study's publication, the FDA announced that it is in the process of updating risk information on the labels of macrolide antibiotics and will review the data from this study. In the meantime, clinicians are advised to be aware of the potential for QT prolongation and arrhythmias in patients taking macrolides, the agency's press release recommended.