In the Journals

Macrolide antibiotics not linked to higher short-term risk for ventricular arrhythmia in older patients

In older patients, macrolide antibiotics were not associated with elevated 30-day risk for ventricular arrhythmia, according to results of a population-based retrospective cohort study.

Previous research has been inconsistent as to whether macrolide antibiotics confer elevated risk for ventricular arrhythmia and death, but the FDA in 2013 began requiring the labels of macrolide antibiotics to warn about such risks, according to the study background.

Amit X. Garg, MD, PhD, and colleagues conducted a propensity-matched study of 616,359 patients assigned macrolide antibiotics (azithromycin, clarithromycin or erythromycin) compared with 705,132 patients assigned nonmacrolide antibiotics (amoxicillin, cefuroxime or levofloxacin). All patients were aged 65 years and older and filled a new prescription for their antibiotic between 2002 and 2013.

The primary outcome was presentation to the ED with or hospitalization for ventricular arrhythmia within 30 days of a new prescription. The secondary outcome was all-cause mortality at 30 days. In addition to an overall analysis, the researchers conducted subgroup analyses based on presence of chronic kidney disease, presence of congestive HF, presence of CAD and use of other medications known to prolong the QT interval.

Compared with the nonmacrolide group, the macrolide group did not have elevated risk for 30-day ventricular arrhythmia (0.03% vs. 0.03%; RR = 1.06; 95% CI, 0.83-1.86), but did have reduced risk for 30-day all-cause mortality (0.62% vs. 0.76%; RR = 0.82; 95% CI, 0.78-0.86), according to the researchers.

There was no interaction between chronic kidney disease, congestive HF, CAD and use of other QT-prolonging drugs and risk for 30-day ventricular arrhythmia or 30-day all-cause mortality.

“In contrast to prior studies, we found that these variables did not significantly alter the association between macrolide antibiotic use and our outcomes,” Garg, director of the Institute for Clinical Evaluative Services western facility in London, Ontario, Canada, and colleagues wrote. “Nonetheless, these findings should be interpreted with caution, and physicians should always consider a patient’s baseline risk for adverse events before prescribing macrolides or other antibiotics. ... These findings are reassuring for health care providers who prescribe macrolide antibiotics to a wide range of patients in routine care.” – by Erik Swain

Disclosure: Garg reports receiving institutional research funding from Pfizer. The other researchers report no relevant financial disclosures.

In older patients, macrolide antibiotics were not associated with elevated 30-day risk for ventricular arrhythmia, according to results of a population-based retrospective cohort study.

Previous research has been inconsistent as to whether macrolide antibiotics confer elevated risk for ventricular arrhythmia and death, but the FDA in 2013 began requiring the labels of macrolide antibiotics to warn about such risks, according to the study background.

Amit X. Garg, MD, PhD, and colleagues conducted a propensity-matched study of 616,359 patients assigned macrolide antibiotics (azithromycin, clarithromycin or erythromycin) compared with 705,132 patients assigned nonmacrolide antibiotics (amoxicillin, cefuroxime or levofloxacin). All patients were aged 65 years and older and filled a new prescription for their antibiotic between 2002 and 2013.

The primary outcome was presentation to the ED with or hospitalization for ventricular arrhythmia within 30 days of a new prescription. The secondary outcome was all-cause mortality at 30 days. In addition to an overall analysis, the researchers conducted subgroup analyses based on presence of chronic kidney disease, presence of congestive HF, presence of CAD and use of other medications known to prolong the QT interval.

Compared with the nonmacrolide group, the macrolide group did not have elevated risk for 30-day ventricular arrhythmia (0.03% vs. 0.03%; RR = 1.06; 95% CI, 0.83-1.86), but did have reduced risk for 30-day all-cause mortality (0.62% vs. 0.76%; RR = 0.82; 95% CI, 0.78-0.86), according to the researchers.

There was no interaction between chronic kidney disease, congestive HF, CAD and use of other QT-prolonging drugs and risk for 30-day ventricular arrhythmia or 30-day all-cause mortality.

“In contrast to prior studies, we found that these variables did not significantly alter the association between macrolide antibiotic use and our outcomes,” Garg, director of the Institute for Clinical Evaluative Services western facility in London, Ontario, Canada, and colleagues wrote. “Nonetheless, these findings should be interpreted with caution, and physicians should always consider a patient’s baseline risk for adverse events before prescribing macrolides or other antibiotics. ... These findings are reassuring for health care providers who prescribe macrolide antibiotics to a wide range of patients in routine care.” – by Erik Swain

Disclosure: Garg reports receiving institutional research funding from Pfizer. The other researchers report no relevant financial disclosures.