Is Amoxicillin Safe If You Have Atrial Fibrillation (A-Fib)?
In our latest question and answer, the pharmacist discusses if amoxicillin can be used if you have been diagnosed with atrial fibrillation.
Is it ok to take amoxicillin if you have signs of afib?
Dec 09, 2022- Amoxicillin is generally considered one of the safer antibiotic choices for people with atrial fibrillation, though rare cases of heart rhythm changes have been reported.
- Macrolide antibiotics like azithromycin and clarithromycin and fluoroquinolone antibiotics like ciprofloxacin and levofloxacin should be avoided in people with atrial fibrillation because they carry a stronger risk of dangerous heart rhythm changes.
- Talk to your doctor about your antibiotic options, as the safest choice depends on what infection is being treated and your other medical conditions.
Answer
While amoxicillin has been rarely linked to causing changes to heart rhythm in case reports, it is generally considered among the safer antibiotic choices if you have been diagnosed with atrial fibrillation.
Other antibiotic classes are considered far more dangerous in those with atrial fibrillation and should be avoided unless you and your doctor determine they represent the best option for you.
What Antibiotics Need To Be Used Cautiously If You Have A Fib?
Several studies have strongly linked two classes of antibiotics with causing potentially dangerous changes to heart rhythm, such as QT-prolongation:
- Macrolides
- Fluoroquinolones
Macrolides include:
- Azithromycin
- Erythromycin
- Clarithromycin
Fluoroquinolones include:
- Ciprofloxacin
- Moxifloxacin
- Levofloxacin
- Ofloxacin
- Gatifloxacin
The FDA (Food and Drug Administration) has released warnings about many of these drugs. For example, in 2013 and 2021, the FDA warned of the risk of QT interval prolongation and potentially fatal 'torsades de pointes' in individuals taking azithromycin:
"The U.S. Food and Drug Administration (FDA) is warning the public that azithromycin (Zithromax or Zmax) can cause abnormal changes in the electrical activity of the heart that may lead to a potentially fatal irregular heart rhythm. Patients at particular risk for developing this condition include those with known risk factors such as existing QT interval prolongation, low blood levels of potassium or magnesium, a slower than normal heart rate, or use of certain drugs used to treat abnormal heart rhythms, or arrhythmias."
All macrolides have been associated with QT interval prolongation and the FDA has released similar warnings for other macrolides, like clarithromycin.
Similar to the warnings for macrolides, caution is also recommended with fluoroquinolone antibiotics in those with certain heart conditions.
As a general rule of thumb, when there are alternative antibiotics available, fluoroquinolones and macrolides are avoided in those with risk factors for arrhythmias, and that would absolutely include if you have been diagnosed with atrial fibrillation. Amoxicillin is often the safer choice.
As mentioned, there are some case reports of amoxicillin causing heart rhythm changes, but it seems quite rare. The FDA has never released a warning about amoxicillin in regard to heart rhythm changes and the vast majority of studies that have found problems with other antibiotics compared those antibiotics to amoxicillin or amoxicillin-type drugs (like this study).
Final Words
So, overall, amoxicillin would generally be seen as the safer choice for someone like you, but of course, there are always other factors that could come into play, like what you are treating, other medical conditions you have, etc...
Be sure to talk to your doctor about any questions or concerns you have.
Thanks for reaching out! Contact us again anytime.
References & sources
- Azithromycin and Levofloxacin Use and Increased Risk of Cardiac Arrhythmia and Death — The Annals of Family Medicine
- Common Antibiotics Increase Risk of Cardiac Arrhythmias, Cardiac Death — American College of Cardiology
- Risks of cardiac arrhythmia and mortality among patients using new-generation macrolides, fluoroquinolones, and β-lactam/β-lactamase inhibitors: a Taiwanese nationwide study — PubMed
- Amoxicillin Prescribing Information — AccessFDA
- FDA Drug Safety Communication: Azithromycin (Zithromax or Zmax) and the risk of potentially fatal heart rhythms — FDA
- FDA Drug Safety Communication: FDA review finds additional data supports the potential for increased long-term risks with antibiotic clarithromycin (Biaxin) in patients with heart disease — FDA
Glossary — Terms in This Answer
- Atrial fibrillation
- A heart condition where the upper chambers of the heart beat irregularly and too fast, disrupting normal blood flow.
- Antibiotic
- A medication that kills or slows the growth of bacteria to treat infections.
- QT-prolongation
- An abnormal lengthening of the electrical signal in the heart that can lead to dangerous irregular heartbeats.
- Macrolides
- A class of antibiotics that includes drugs like azithromycin and erythromycin, used to treat various bacterial infections.
- Fluoroquinolones
- A class of antibiotics that includes drugs like ciprofloxacin and levofloxacin, used to treat bacterial infections.
- Arrhythmias
- Irregular or abnormal heartbeats that may be too fast, too slow, or out of rhythm.
- Torsades de pointes
- A potentially fatal type of irregular heartbeat that can cause loss of consciousness or sudden cardiac death.
- Amoxicillin
- A penicillin-type antibiotic commonly used to treat bacterial infections and generally considered safer for people with heart rhythm problems.
Dr. Brian Staiger, PharmD
Doctor of Pharmacy, board certified clinical pharmacist (BCPS), American Herbalist Guild, Medication Therapy Management certified
Brian Staiger, PharmD, BCPS, is a licensed pharmacist with more than 13 years of experience across retail pharmacy, clinical pharmacy, medication safety, pharmacy program development, and healthcare administration. He is the founder of HelloPharmacist.com, where he helps patients...
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