Can Amoxicillin Cause Heart Palpitations?
If your heart starts racing, pounding or fluttering while you are taking amoxicillin, it is understandable to wonder whether the antibiotic is responsible.
Heart palpitations are not considered a common side effect of amoxicillin itself. However, the infection being treated, fever, dehydration, anxiety, another medication or — rarely — a serious allergic reaction may affect your heart rate or make your heartbeat more noticeable.
Does Amoxicillin Cause Heart Palpitations?
- Heart palpitations are not a typical common side effect of amoxicillin.
- The infection itself, especially when accompanied by fever, may cause a faster or stronger heartbeat.
- Vomiting or diarrhea may contribute to dehydration, which can make the heart beat faster.
- Stress or anxiety about illness or medication can make your heartbeat more noticeable.
- A serious allergic reaction to amoxicillin can affect breathing, blood pressure and pulse and requires emergency care.
- If you take several medicines, another drug or drug combination may be contributing to the palpitations.
- Do not stop prescribed amoxicillin simply because you notice palpitations without contacting the prescribing clinician, unless you are developing signs of a serious allergic reaction requiring urgent medical care.
What Is Amoxicillin?
Amoxicillin is an antibiotic in the penicillin family. It is used to treat certain infections caused by susceptible bacteria.
Doctors may prescribe it for bacterial infections involving areas such as the ears, respiratory tract, urinary tract, skin or other appropriate sites, depending on the individual diagnosis.
Amoxicillin is also used as part of certain combination treatments, including some regimens for Helicobacter pylori infection.
Antibiotics do not treat viral illnesses, and they should be taken exactly according to the prescribing clinician’s instructions.
What Are Common Amoxicillin Side Effects?
Heart palpitations are not among the main common side effects listed in standard patient information for amoxicillin.
Nausea
Some people experience nausea while taking amoxicillin.
Vomiting
Vomiting can occur and may contribute to fluid loss if it becomes persistent.
Diarrhea
Diarrhea is another recognized gastrointestinal side effect. Severe, persistent, watery or bloody diarrhea requires medical attention.
So Why Did My Palpitations Start After Amoxicillin?
Timing alone does not prove that amoxicillin caused the palpitation.
A patient who starts an antibiotic is usually already ill. Fever, infection, reduced fluid intake, vomiting, diarrhea, pain, poor sleep and anxiety can all occur around the same time.
Any of these factors may make your heart beat faster or make you more aware of it.
In addition, some people experience heart palpitation symptoms such as skipped beats, fluttering or pounding from causes unrelated to the antibiotic.
If symptoms recur after each dose, become more frequent or continue after the infection improves, tell your prescribing clinician.
The Infection May Be Affecting Your Heart Rate
Fever
During fever and acute illness, heart rate may increase as part of the body’s normal physiological response.
Dehydration
Fever, vomiting, diarrhea and reduced fluid intake can contribute to dehydration and a faster heartbeat.
Anxiety & Stress
Feeling unwell or worrying about a new medicine can increase awareness of the heartbeat and sometimes increase heart rate.
Palpitations With Signs of an Amoxicillin Allergy
Penicillin antibiotics, including amoxicillin, can rarely cause a serious allergic reaction known as anaphylaxis.
Anaphylaxis can affect the airways and circulation and may cause a rapid or weak pulse.
Seek emergency medical care immediately if taking amoxicillin is followed by symptoms such as:
- Difficulty breathing
- Wheezing
- Swelling of the face, lips, tongue or throat
- Difficulty swallowing
- Widespread hives or severe itching
- Severe dizziness or fainting
- A rapid, weak pulse
- Collapse or loss of consciousness
A severe allergic reaction is an emergency and is different from an isolated awareness of your heartbeat.
Could Another Medicine Be Causing the Palpitations?
Possibly. When a new symptom begins during treatment, it is important to review all medicines and supplements, not just the newest prescription.
Some people taking antibiotics are also using medicines for fever, cough, congestion, breathing problems or other symptoms. Certain medicines can affect heart rate or heartbeat awareness.
Combination therapies also contain more than one drug, so the adverse effects and interactions of each medicine need to be considered individually.
For a broader explanation, see our guide to medications and heart palpitations .
Why Is Amoxicillin Sometimes Given to People With Heart Conditions?
Older information sometimes gives the impression that amoxicillin is routinely prescribed to people with heart disease. That is not accurate.
Current infective-endocarditis prevention guidance reserves antibiotic prophylaxis before certain dental procedures for selected people at particularly high risk of serious complications.
Examples include some people with:
- Prosthetic heart valves
- Prosthetic material used for certain heart-valve repairs
- A previous history of infective endocarditis
- Certain congenital heart conditions
- A heart transplant with specific valve disease
Whether antibiotic prophylaxis is appropriate depends on the patient’s exact heart condition and the procedure being performed.
What Should You Do If Palpitations Start While Taking Amoxicillin?
Check for Allergy Symptoms
Breathing difficulty, facial or throat swelling, widespread hives, severe dizziness or collapse require emergency attention.
Describe the Palpitations
Note whether your heart feels fast, pounding, fluttering, irregular or as though it is skipping beats.
Look at the Timing
Record whether symptoms occur soon after each dose or mainly during fever, pain, dehydration or anxiety.
Review All Medicines
Tell your doctor or pharmacist about prescription medicines, over-the-counter products, supplements and stimulants.
Contact the Prescriber
If palpitations are new, recurrent or clearly linked to starting treatment, contact the clinician who prescribed the antibiotic for individualized advice.
Consider Heart-Rhythm Evaluation
Persistent, recurrent, very fast or irregular palpitations may require an ECG or longer heart-rhythm monitoring.
Should You Stop Amoxicillin Because of Palpitations?
Do not stop a prescribed antibiotic solely because of an isolated palpitation without discussing the symptom with your healthcare professional.
Stopping an antibiotic too early can leave the bacterial infection incompletely treated.
However, suspected serious allergic reactions are different and require immediate medical care.
If you are unsure whether your symptoms represent an allergy or another serious reaction, seek prompt medical advice rather than trying to diagnose the reaction yourself.
Timing Is Important, But It Does Not Prove Cause
When a patient tells me, “My palpitations started the day I began amoxicillin,” I take that timing seriously.
But I also ask why the antibiotic was prescribed in the first place. Was there fever? Significant infection? Vomiting or diarrhea? Dehydration? Anxiety? Other medicines?
I also want to know whether the heartbeat feels fast, irregular, pounding or like skipped beats and whether dizziness or chest symptoms occur.
The goal is to determine whether the medicine is likely involved or whether another explanation needs attention.
When the Pattern Suggests Further Evaluation
If the palpitations occur only once briefly, that is different from symptoms that continue repeatedly throughout the day.
If your heartbeat symptoms seem almost continuous, our guide to constant heart palpitations explains why persistent symptoms deserve a closer look.
If you also feel faint or lightheaded, see dizziness and heart palpitations because the combination may affect how urgently your symptoms should be assessed.
When Palpitations Need Urgent Medical Care
Seek urgent or emergency medical care if palpitations occur with:
- Chest pain or significant chest pressure
- Fainting or loss of consciousness
- Severe shortness of breath
- Severe dizziness or near-fainting
- Severe weakness or collapse
- Signs of a serious allergic reaction
Do not assume a serious symptom is simply a harmless antibiotic side effect.
Amoxicillin and Heart Palpitations: FAQs
Is heart racing a common side effect of amoxicillin?
No. A racing heart or heart palpitations are not listed among the usual common adverse effects of amoxicillin.
Infection, fever, dehydration, anxiety, another medicine or a serious allergic reaction may sometimes provide another explanation.
Can amoxicillin cause an irregular heartbeat?
Amoxicillin is not generally regarded as a common direct cause of arrhythmia. If you develop a persistent or clearly irregular heartbeat while taking it, the rhythm should be evaluated rather than automatically attributed to the antibiotic.
Can an amoxicillin allergy cause a fast heartbeat?
A severe allergic reaction such as anaphylaxis can affect blood pressure and circulation and may cause a rapid, weak pulse.
Breathing difficulty, swelling, widespread hives, severe dizziness or fainting require emergency care.
Can infection cause heart palpitations?
Yes. Fever, pain, dehydration, physiological stress and anxiety during an illness may all increase heart rate or make the heartbeat more noticeable.
Can diarrhea from amoxicillin cause palpitations?
Significant diarrhea can contribute to dehydration and fluid or electrolyte disturbances, which may affect heart rate or heartbeat awareness.
Severe, watery, persistent or bloody diarrhea requires medical assessment.
Should I stop amoxicillin if I have palpitations?
Do not stop prescribed amoxicillin solely because of an isolated palpitation without contacting the prescribing clinician.
A suspected severe allergic reaction is different and requires immediate emergency care.
Should I have an ECG?
An ECG may be appropriate when palpitations are new, recurrent, prolonged, very fast or irregular.
If episodes are intermittent, longer heart-rhythm monitoring may sometimes be needed because a short ECG may not capture them.
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Evidence Used for This Article
- MedlinePlus. Amoxicillin Drug Information .
- U.S. Food and Drug Administration. AMOXIL Prescribing Information .
- Mayo Clinic. Penicillin Allergy: Symptoms and Causes .
- American Heart Association. Infective Endocarditis .
- American Heart Association. Symptoms, Diagnosis and Monitoring of Arrhythmia .