Medication Palpitation Risk Checker
Check Your Medication Risk
Risk Assessment
How This Tool Works
This tool uses data from the article to calculate your risk based on:
- Medication types selected
- Age over 65 years
- Presence of kidney disease
Based on the Brigham and Women's Medication-Induced Arrhythmia Risk Score. This is for educational purposes only and doesn't replace medical advice.
Feeling your heart race out of nowhere-like it’s pounding in your chest, fluttering, or skipping beats-can be terrifying. If you’ve recently started a new medication or changed a dose, that sensation might not be anxiety. It could be your drug causing palpitations or a rapid heartbeat. This isn’t rare. Around 1 in 5 people who develop abnormal heart rhythms do so because of a medication they’re taking. And many of these cases are preventable.
What Medications Can Trigger Palpitations?
You might not expect common prescriptions or over-the-counter pills to affect your heart. But dozens of widely used drugs can disrupt your heart’s electrical system, leading to palpitations or a fast heartbeat (tachycardia). Here are the most common culprits:- Asthma inhalers like albuterol (Ventolin, ProAir) can spike your heart rate by 15-25 beats per minute within 30 minutes. This happens because they stimulate beta-2 receptors, which also affect the heart. If you’re using your inhaler more than recommended, the effect can build up.
- Antibiotics such as azithromycin (Zithromax) and levofloxacin (Levaquin) are known to prolong the QT interval-the time your heart takes to recharge between beats. A longer QT interval can lead to dangerous rhythms like torsades de pointes. Studies show azithromycin increases the risk of rapid heartbeat by more than twice compared to antibiotics like amoxicillin.
- Decongestants like pseudoephedrine (Sudafed) and phenylephrine are designed to shrink nasal passages, but they also constrict blood vessels and raise your heart rate. At standard doses (60 mg), pseudoephedrine can increase your heart rate by 10-20 beats per minute. That’s enough to cause noticeable palpitations, especially in older adults or those with high blood pressure.
- Thyroid medication like levothyroxine (Synthroid) is essential for many, but too much can overstimulate your metabolism-and your heart. When your TSH level drops below 0.1 mIU/L, palpitations occur in 8-12% of patients. Many people don’t realize their dose is too high until they start feeling their heart race.
- Antidepressants like amitriptyline (a tricyclic) and citalopram (Celexa) can delay heart repolarization. Citalopram doses above 40 mg/day are especially risky in older adults. Even SSRIs like sertraline (Zoloft) are safer alternatives when heart rhythm is a concern.
- Newer weight-loss drugs like semaglutide (Ozempic, Wegovy) are linked to a modest but consistent increase in heart rate-3 to 5 beats per minute on average. For most, this is harmless. But if you already have heart disease or arrhythmias, even a small increase can trigger symptoms.
Why Does This Happen?
Your heart beats because of electrical signals traveling through specialized cells. Medications interfere with the flow of sodium, potassium, or calcium ions in those cells. When these ions are blocked or overstimulated, the heart’s rhythm gets thrown off. Some drugs, like azithromycin or citalopram, block a specific potassium channel (hERG), which delays the heart’s recovery phase. This is measured as QT prolongation on an ECG. When QT gets too long, the heart can develop a dangerous spiral rhythm called torsades de pointes-which can turn into cardiac arrest if not treated immediately. Other drugs, like albuterol or pseudoephedrine, trigger the sympathetic nervous system. This is your body’s “fight or flight” response. It releases adrenaline, which makes your heart beat faster and harder. That’s why you feel your pulse in your throat or chest-even if your blood pressure is normal.How Doctors Evaluate Medication-Induced Palpitations
If you report palpitations, your doctor won’t just assume it’s stress or caffeine. They’ll follow a clear, step-by-step process:- Medication review: Every single drug you take-including supplements, herbal products, and OTC pills-is listed. New additions or dose changes in the last 72 hours are red flags.
- ECG (electrocardiogram): A 12-lead ECG checks your heart’s rhythm and measures the QTc interval. A QTc over 450 ms in men or 460 ms in women is concerning. Over 500 ms is high risk.
- Blood tests: Low potassium (below 3.5 mmol/L) or low magnesium (below 1.7 mg/dL) make arrhythmias much more likely. Thyroid levels (TSH) are checked if you’re on levothyroxine.
- Monitoring: If the ECG looks normal but symptoms persist, a 24- to 48-hour Holter monitor may be used. It catches intermittent rhythms that a single ECG misses-about 40% of cases.
What to Do If You’re Experiencing Palpitations
Your next steps depend on how severe your symptoms are and your risk level:- Mild cases (palpitations without dizziness, chest pain, or fainting, QTc under 500 ms): Your doctor may recommend continuing the medication but monitoring closely. They’ll check your electrolytes and do a follow-up ECG in a week. Often, symptoms fade as your body adjusts.
- Moderate cases (palpitations with lightheadedness, QTc 480-500 ms): Dose reduction is the first move. For example, lowering levothyroxine from 125 mcg to 100 mcg can cut palpitations in half. Studies show 60-70% of patients improve within 72 hours of adjusting the dose.
- High-risk cases (QTc over 500 ms, fainting, or signs of torsades): The medication is stopped immediately. If you’re on azithromycin and your QTc is dangerously long, switching to amoxicillin is the standard move. In cancer patients who need drugs that cause arrhythmias, beta-blockers like metoprolol are often added preventively to reduce risk by 45%.
How to Prevent Medication-Induced Heart Problems
The best way to avoid this issue? Prevention. Here’s what works:- Get a baseline ECG before starting any new medication known to affect the heart-especially antibiotics, antidepressants, or thyroid drugs.
- Don’t combine QT-prolonging drugs. Taking two of them (like azithromycin + citalopram) increases your risk of dangerous arrhythmias by nearly six times.
- Check your potassium and magnesium. Eat bananas, spinach, almonds, or consider a supplement if your levels are low. These minerals help your heart stay stable.
- Use a symptom journal. Write down when you feel palpitations, what you took, and your heart rate (if you have a smartwatch). This helps spot patterns. One patient noticed her heart raced every time she took Sudafed after 6 p.m.-she stopped taking it at night and the problem vanished.
- Ask your pharmacist. They can flag dangerous interactions. Many pharmacies now have automated alerts when you pick up a drug that could interact with others you’re taking.
What Patients Are Saying
Real-world experiences confirm the data. On patient forums, people describe:- Starting azithromycin for a sinus infection and waking up with a heart that felt like it was “banging against my ribs.”
- Feeling fine on levothyroxine for years-until a dose increase led to waking up with their heart pounding at 3 a.m., every night.
- Switching from citalopram to sertraline and having palpitations disappear within 10 days, with no drop in mood improvement.
- Using pseudoephedrine for allergies and realizing their heart rate jumped from 70 to 110 bpm-without any other symptoms.
What’s Changing in 2025
Hospitals are getting smarter. Most now use electronic health systems that block dangerous prescriptions before they’re written. If your doctor tries to order azithromycin and your QTc is over 480 ms, the system pops up a warning. In 67% of U.S. hospitals, this already happens. New research is also moving toward personalized medicine. Genetic tests can now identify people who metabolize drugs slowly-making them more prone to side effects. For example, people with a CYP2D6 gene variant are 3.4 times more likely to have heart rate issues from beta-blockers. The European Heart Rhythm Association is tracking 50,000 patients across 15 countries to build better risk models. By late 2025, guidelines will likely update to include genetic risk factors in routine screening.When to Seek Help Immediately
Not all palpitations are dangerous-but some are emergencies. Go to the ER if you have:- Palpitations with chest pain or pressure
- Dizziness, fainting, or near-fainting
- Shortness of breath that doesn’t improve
- Heart rate over 140 bpm that doesn’t slow down
- Feeling like your heart is “fluttering” and then suddenly stops
Can over-the-counter cold medicines cause rapid heartbeat?
Yes. Decongestants like pseudoephedrine (Sudafed) and phenylephrine can increase heart rate by 10-20 beats per minute. Even if you don’t have heart disease, these can trigger palpitations, especially if you’re older, take other medications, or have high blood pressure. Always check labels for these ingredients if you’re prone to heart rhythm issues.
Is it safe to keep taking my antibiotic if I feel palpitations?
Not without evaluation. If you feel your heart racing after starting an antibiotic like azithromycin or levofloxacin, stop taking it and contact your doctor. A simple ECG can check your QT interval. In many cases, switching to a safer antibiotic like amoxicillin resolves the issue without compromising treatment.
Can thyroid medication cause heart palpitations?
Yes. Levothyroxine can cause palpitations if the dose is too high, especially if your TSH level drops below 0.1 mIU/L. This is common when patients adjust their dose without blood tests. The fix is simple: lower the dose and recheck TSH every 6-8 weeks until levels stabilize between 0.5 and 2.0 mIU/L.
Are antidepressants safe for people with heart problems?
Some are, some aren’t. Tricyclics like amitriptyline and high-dose citalopram carry higher heart risks. SSRIs like sertraline and escitalopram are safer options for people with heart conditions. Always tell your psychiatrist about your heart history-they can choose the best drug for you.
How long do medication-induced palpitations last?
It depends. For drugs like albuterol or pseudoephedrine, palpitations usually fade within hours after stopping. For QT-prolonging drugs like azithromycin, it may take days for the heart’s rhythm to return to normal. With thyroid medication, symptoms often improve within 1-2 weeks after a dose adjustment. If palpitations persist beyond 2 weeks after stopping the drug, see a cardiologist.
Can supplements cause palpitations?
Absolutely. Herbal supplements like ephedra, bitter orange, and high-dose green tea extract can stimulate the heart. Even some vitamins-like excessive vitamin D or iodine-can trigger arrhythmias. Always tell your doctor about every supplement you take, even if you think it’s “natural” and safe.