Table 3:

Risk of ventricular arrhythmia associated with current, recent and past use of azithromycin compared with current use of amoxicillin (1-stage pooling)

Exposure*No. (%) of cases
n = 479
No. (%) of controls
n = 1848
OR (95% CI)
Current use of amoxicillin165 (34.4)370 (20.0)1.00 (ref)1.00 (ref)
Use of azithromycin
 Current30 (6.3)88 (4.8)1.05 (0.63–1.74)0.94 (0.50–1.77)
 Recent107 (22.3)483 (26.1)0.60 (0.44–0.83)0.58 (0.38–0.87)
 Past177 (37.0)907 (49.1)0.49 (0.36–0.66)0.52 (0.37–0.73)
  • Note: CI = confidence interval, OR = odds ratio, ref = reference category.

  • * Current = exposure period covered the index date (occurrence of ventricular arrhythmia) or ended within 7 days before the index date; recent = exposure period ended between 7 and 89 days before the index date; past = exposure period ended between 90 and 364 days before the index date.

  • Current users of both azithromycin and other antibiotics were not included in the analysis.

  • Crude ORs were estimated for matched case–control pairs and cannot be calculated directly from the values in this table.

  • § Adjusted for risk factors of ventricular arrhythmia: atrial fibrillation/flutter, cardiomyopathy, coronary artery disease, cerebrovascular disorders, chronic obstructive pulmonary disease, electrolytic imbalance, heart failure, hypertension, diabetes mellitus, lipid disorder, peripheral arterial disease, hypothyroidism, prior use of antiarrhythmic drugs, concomitant use of drugs known to cause hypokalemia, and concomitant use of drugs known to prolong QT interval.