Can Zithromax (azithromycin) worsen Congestive Heart Failure (CHF)?

From the Guidelines

Yes, Z-Pak (azithromycin) can potentially worsen congestive heart failure (CHF) in some patients. Azithromycin belongs to the macrolide antibiotic class, which has been associated with QT interval prolongation and increased risk of cardiac arrhythmias, particularly in patients with pre-existing heart conditions 1. For patients with CHF, this medication should be used with caution and only when the benefits outweigh the risks. The risk is higher in elderly patients, those with electrolyte abnormalities (especially low potassium or magnesium), and patients taking other medications that can prolong the QT interval.

Key Considerations

• If a patient with CHF needs antibiotic treatment, healthcare providers should consider alternative antibiotics with less cardiac risk when appropriate.
• Patients with CHF who are prescribed azithromycin should be monitored for worsening heart failure symptoms such as increased shortness of breath, swelling, or fatigue.
• The cardiac effects are related to azithromycin's ability to block certain potassium channels in heart cells, which affects cardiac repolarization and can lead to electrical instability in the heart.

Clinical Guidance

• A Medicaid cohort study found a small but absolute increase in cardiovascular deaths associated with azithromycin use, particularly in patients with high baseline risk of cardiovascular disease 1.
• The FDA has issued a warning about the potential for azithromycin to cause abnormalities in the electrical activity of the heart, leading to serious irregularities in heart rhythm 1.
• Alternative antibiotics with less cardiac risk should be considered for patients with CHF, and patients should be closely monitored for signs of worsening heart failure when azithromycin is prescribed.

From the FDA Drug Label

Prolonged cardiac repolarization and QT interval, imparting a risk of developing cardiac arrhythmia and torsades de pointes, have been seen in treatment with macrolides, including azithromycin Cases of torsades de pointes have been spontaneously reported during postmarketing surveillance in patients receiving azithromycin Providers should consider the risk of QT prolongation which can be fatal when weighing the risks and benefits of azithromycin for at-risk groups including: patients with known prolongation of the QT interval, a history of torsades de pointes, congenital long QT syndrome, bradyarrhythmias or uncompensated heart failure patients on drugs known to prolong the QT interval patients with ongoing proarrhythmic conditions such as uncorrected hypokalemia or hypomagnesemia, clinically significant bradycardia, and in patients receiving Class IA (quinidine, procainamide) or Class III (dofetilide, amiodarone, sotalol) antiarrhythmic agents.

Azithromycin (Zpak) may worsen Congestive Heart Failure (CHF), particularly in patients with uncompensated heart failure due to the risk of QT prolongation, which can be fatal 2.

From the Research

Zpak and CHF

• Zpak, also known as azithromycin, is an antibiotic that has been associated with an increased risk of cardiac arrhythmia and death, particularly in patients with pre-existing heart conditions 3.
• A study published in the Annals of Family Medicine found that azithromycin use was associated with a significantly increased risk of death and serious arrhythmia compared to amoxicillin, especially during the first 5 days of treatment 3.
• Another study published in the Journal of Cardiovascular Development and Disease discussed the management of arrhythmias in heart failure patients, highlighting the importance of considering the underlying structural heart disease and the severity of heart failure when managing arrhythmias 4.

Cardiac Risk Factors

• A study published in Pharmacotherapy found that despite the 2012 FDA warning on the risk of potentially fatal heart rhythms associated with azithromycin, a significant number of azithromycin prescriptions were still dispensed to patients with pre-existing cardiac conditions or those using QT-interval-prolonging drugs 5.
• The study also found that the prevalence of cardiac risk factors among patients prescribed azithromycin remained essentially unchanged before and after the FDA warning was issued 5.
• The management of heart failure patients requires careful consideration of various factors, including the use of medications that may exacerbate heart failure symptoms, such as azithromycin 6.

Heart Failure Management

• A study published in the Journal of Cardiovascular Development and Disease discussed the importance of optimizing heart failure therapy to manage arrhythmias in heart failure patients 4.
• Another study published in Heart Failure Reviews provided practical guidelines for exercise prescription in patients with chronic heart failure, highlighting the importance of considering the patient's clinical condition and comorbidities when prescribing exercise 7.
• The study also emphasized the need for careful consideration of medications, implantable devices, and other factors when managing heart failure patients 7.