What Is Atrial Fibrillation (AFib)?

AFib is an irregular, often rapid heartbeat that occurs when the upper chambers of the heart (atria) beat out of sync with the lower chambers (ventricles). It can be occasional, persistent, or permanent.

Common symptoms include:

Heart palpitations or fluttering

Shortness of breath

Dizziness or lightheadedness

Fatigue or chest discomfort

In some people, AFib causes no noticeable symptoms—but it can still increase the risk of stroke, heart failure, and blood clots over time.

How Can Medications Trigger AFib?

Some drugs can impact the electrical signals of the heart by:

Increasing adrenaline-like activity

Disrupting electrolyte balance

Stimulating the nervous system

Interacting with other medications or pre-existing conditions

Let’s look at several categories of medications that have been linked to AFib onset or aggravation, particularly in sensitive individuals or those with underlying heart issues.

1. Decongestants and Cold Medications

Over-the-counter cold and flu treatments often contain pseudoephedrine or phenylephrine—both of which are stimulants.

These ingredients may:

Raise blood pressure

Increase heart rate

Trigger irregular rhythms in predisposed individuals

While safe for many, these can cause issues in people with heart conditions, hypertension, or arrhythmia history.

2. Stimulant Medications for ADHD

Drugs like amphetamine (Adderall) and methylphenidate (Ritalin) are designed to increase alertness and focus. But in some cases, they can:

Accelerate the heart rhythm

Increase sympathetic nervous system activity

Heighten risk for palpitations or AFib

This doesn’t mean they’re off-limits, but regular cardiac monitoring is often recommended—especially in adults.

3. Certain Antidepressants

While most antidepressants are safe for the heart, some—particularly tricyclic antidepressants (TCAs) and certain SSRIs—have been associated with changes in heart rhythm.

Examples include:

Amitriptyline

Nortriptyline

Citalopram (at high doses)

These may prolong QT interval or alter conduction pathways, creating a higher chance of arrhythmias in vulnerable patients.

4. Corticosteroids

Medications like prednisone or methylprednisolone, often used to treat inflammation or immune issues, have been reported to increase the risk of AFib, especially in:

Older adults

Patients with high blood pressure

Those on high-dose or long-term steroid use

Mechanisms may include fluid retention, blood pressure elevation, or electrolyte imbalances.

5. Thyroid Medications

Overcorrecting low thyroid levels with levothyroxine or similar medications can push the body into a hyperthyroid state, which is a known risk factor for AFib.

Signs of overmedication may include:

Restlessness

Heat intolerance

Rapid or irregular heartbeats

Regular blood work is crucial to ensure proper thyroid hormone balance.

6. Asthma and COPD Medications

Some bronchodilators—especially beta-agonists like albuterol—can stimulate the heart and lead to temporary rhythm disturbances.

This is more likely when:

Used in high doses

Combined with steroids or stimulants

Pre-existing heart issues are present

Newer, targeted inhalers are often safer—but caution is still advised with frequent use.

7. Cancer Treatment Drugs

Certain chemotherapy agents and targeted cancer therapies can affect heart function, including rhythm stability.

Examples include:

Ibrutinib (used for blood cancers)

Doxorubicin

Some immunotherapies

These medications are closely monitored by oncologists, but AFib may occur even months after treatment ends.

8. Excessive Use of Supplements or Energy Products

Not all AFib triggers come from prescriptions. Overuse of:

Caffeine pills

Pre-workout supplements

Weight loss stimulants

Herbal products with ephedra or guarana

...can overstimulate the heart, especially when combined with dehydration, heat, or fasting.

These substances often bypass FDA regulation—making awareness critical.

When to Be Concerned

You should talk to your doctor if:

You notice fluttering, skipped beats, or pounding heart

Symptoms appear after starting a new medication

You experience dizziness, fainting, or persistent fatigue

It’s especially important if you have:

High blood pressure

Diabetes

A family history of heart rhythm issues

How to Reduce Your Risk

Always share your full medication list, including supplements.

Avoid mixing stimulants (like decongestants + caffeine).

Monitor your heart rate with smartwatches or devices if recommended.

Stay hydrated and avoid electrolyte imbalances.

Request regular ECGs if you’re on medications that can affect rhythm.

It’s easy to assume that prescriptions are always safe if they’re approved and prescribed—but the truth is, some medications may trigger unexpected effects, especially when it comes to heart rhythm. One of the lesser-known risks associated with certain drugs is atrial fibrillation, or AFib—a type of irregular heartbeat that can lead to more serious complications if left unaddressed.