From the Guidelines
Azithromycin is associated with significant cardiac effects, including QT interval prolongation, which can lead to potentially fatal arrhythmias like Torsades de Pointes, as supported by recent studies 1. The cardiac effects of azithromycin can be dose-dependent and usually reversible upon discontinuation of the medication.
Key Cardiac Effects
- QT interval prolongation
- Serious arrhythmias
- Increased risk for sudden death
- Non-pause-dependent polymorphic ventricular tachycardia The risk of these cardiac effects is higher in patients with pre-existing heart conditions, electrolyte abnormalities (particularly low potassium or magnesium), or in those taking other medications that also prolong the QT interval, as noted in a study published in the Journal of the American College of Cardiology 1.
Patient Risk Factors
- Advanced age
- Female sex
- Heart disease
- Use of other QT prolonging medication
- Reduced drug elimination
- Bradycardia
- Prolonged QT interval before therapy
- Genetic predisposition Healthcare providers should obtain baseline ECGs before starting azithromycin in high-risk patients and monitor for symptoms like palpitations, dizziness, or syncope during treatment, which could indicate cardiac complications, as suggested by a guideline published in Thorax 1.
From the FDA Drug Label
Cardiovascular: Chest pain Cardiovascular: Palpitations, chest pain. Cardiovascular: Arrhythmias including ventricular tachycardia and hypotension There have been rare reports of QT prolongation and torsades de pointes.
The common cardiac effects of azithromycin include chest pain and palpitations. Additionally, there have been rare reports of arrhythmias, including ventricular tachycardia and hypotension, as well as QT prolongation and torsades de pointes 2, 2, 2.
From the Research
Common Cardiac Effects of Azithromycin
The cardiac effects of azithromycin have been studied in various research papers. Some of the common cardiac effects include:
- QTc interval prolongation: Azithromycin has been shown to prolong the QTc interval, which can increase the risk of torsade de pointes and other arrhythmias 3, 4, 5.
- Torsade de pointes: There have been case reports of azithromycin-induced torsade de pointes, particularly in patients with underlying heart disease or other risk factors 3, 4.
- Cardiovascular death: Some studies have suggested that azithromycin may increase the risk of cardiovascular death, particularly in patients with high baseline risk 6.
- Ventricular contraction suppression: Azithromycin has been shown to suppress ventricular contraction in animal studies, which could potentially increase the risk of cardiac complications 7.
Risk Factors for Cardiac Effects
Certain risk factors may increase the likelihood of cardiac effects from azithromycin, including:
- Female sex: Women may be at higher risk of azithromycin-induced QTc interval prolongation and torsade de pointes 3, 4.
- Older age: Elderly patients may be at higher risk of cardiac complications from azithromycin due to underlying heart disease or other comorbidities 3, 4, 5.
- Heart disease: Patients with pre-existing heart disease may be at higher risk of cardiac complications from azithromycin 3, 4, 5, 6.
- QTc interval prolonging drugs: Concomitant use of other QTc interval prolonging drugs may increase the risk of torsade de pointes and other arrhythmias 3, 4.
- Hypokalemia: Low potassium levels may increase the risk of cardiac complications from azithromycin 4.
- Bradycardia: Slow heart rate may increase the risk of cardiac complications from azithromycin 3, 4.