Researchers from National Taiwan University have found a small increased risk for ventricular arrhythmia and cardiovascular death associated with the antibiotics azithromycin and moxifloxacin compared with amoxicillin-clavulanate.
“Despite the significantly increased relative risk associated with these antibiotics, the absolute risks were very small, especially in patients without underlying cardiovascular disease,” the researchers wrote in Clinical Infectious Diseases.
The researchers conducted a nationwide, population-based study to compare the cardiovascular risks associated with macrolides, fluoroquinolones and beta-lactam/beta-lactamase inhibitors compared with amoxicillin-clavulanate. They used data from the Taiwan National Health Insurance Database and identified 10,684,100 patients who were prescribed oral azithromycin, clarithromycin, moxifloxacin, levofloxacin, ciprofloxacin or amoxicillin-clavulanate at an outpatient visit from January 2001 to November 2011.
Azithromycin was associated with a significant increased risk for ventricular arrhythmia (OR=4.32; 95% CI, 2.95-6.33) and cardiovascular death (OR=2.62; 95% CI, 1.69-4.06) compared with amoxicillin-clavulanate. Moxifloxacin also was associated with increased risk for ventricular arrhythmia (OR=3.3; 95% CI, 2.07-5.25) and cardiovascular death (OR=2.31; 95% CI, 1.39-3.84). The risk for cardiovascular death was increased with levofloxacin (OR=1.77; 95% CI, 1.22-2.59).
Within the macrolide class, azithromycin significantly increased the risk of ventricular arrhythmia (OR=6.13; 95% CI, 3.68-10.24) and cardiovascular death (OR=5.72; 95% CI, 3.14-10.42) compared with clarithromycin. Among fluoroquinolones, moxifloxacin (OR=2.51; 95% CI, 1.28-4.94) and levofloxacin (OR=2.36; 95% CI, 1.43-3.9) increased the risk for cardiovascular death compared with ciprofloxacin.
The absolute cardiovascular risk among patients without underlying cardiovascular disease was low. For patients with underlying cardiovascular disease, the absolute risk for ventricular arrhythmia per 1,000 individuals was 1.12 for azithromycin and 0.85 for moxifloxacin, compared with 0.42 for amoxicillin-clavulanate. The absolute risk for cardiovascular death per 1,000 individuals was 1.45 for azithromycin, 1.02 for moxifloxacin and 0.95 for levofloxacin, vs. 0.5 for amoxicillin-clavulanate.
“Additional research is needed to determine whether these increased risks are due to the drugs or related to the severity of infection or the pathogens themselves,” the researchers wrote.
Disclosure: The researchers report no relevant financial disclosures.