The excess cardiovascular mortality previously observed with azithromycin use is attributable to the infection being treated, not the antibiotic, a New England Journal of Medicine study finds.

Using Danish registries, researchers compared 1.1 million episodes of azithromycin use with either 1.1 million episodes of no antibiotic use or 7.4 million episodes of penicillin V use among adults.

The risk for cardiovascular death was roughly three times higher with current azithromycin use than with no antibiotic use. However, cardiovascular death rates did not differ between azithromycin and penicillin. This indicates, the authors write, that “the increased risk … observed in the comparison with no antibiotic use was entirely attributable to the risk of death associated with acute infection” or some other risk factor in patients receiving antibiotics.

The authors add that while previous research showed a link between azithromycin and cardiovascular mortality in a higher-risk (Medicaid) population, the current study “shows that this effect is not present in the general population.”

NEJM commentators still highlight the potential risk for QT prolongation with use of macrolides and emphasize caution in their use for patients with preexisting cardiovascular conditions.

Source: NEJM