Propafenone

How Does Propafenone Work?

Propafenone works primarily by blocking fast sodium channels in cardiac muscle cells and conduction tissue. This slows the speed at which electrical signals travel through the heart — reducing abnormal automaticity, slowing conduction velocity, and interrupting the reentrant electrical circuits that cause arrhythmias like atrial fibrillation and PSVT.

What makes propafenone unique among Class IC antiarrhythmics is its additional pharmacological properties. It has mild beta-adrenergic blocking activity (similar to a weak beta-blocker), mild calcium channel blocking activity, and at higher concentrations can slightly prolong the cardiac action potential. These combined effects make it effective for both rhythm control and partial rate control in atrial fibrillation.

Propafenone is metabolized primarily by the liver enzyme CYP2D6, with additional involvement of CYP3A4 and CYP1A2. About 6% of Caucasians are poor metabolizers of CYP2D6, which leads to higher drug concentrations and more pronounced beta-blocking effects at standard doses. Your cardiologist will titrate your dose carefully based on your response and any side effects.

How Hard Is It to Find Propafenone in Stock?

As of 2026, propafenone is not on the FDA's national drug shortage list. Multiple generic manufacturers — including ANI Pharmaceuticals, Strides Pharma, and Aurobindo — produce both the immediate-release tablet and extended-release capsule formulations, providing supply chain redundancy. The immediate-release tablets (150 mg, 225 mg, 300 mg) are generally well-stocked at large chain pharmacies.

However, localized stocking gaps do occur, particularly for the extended-release capsule formulation (225 mg, 325 mg, 425 mg) and at smaller independent pharmacies. Patients who are prescribed propafenone ER may encounter more difficulty finding it in stock compared to the IR tablets. Large chain pharmacies such as Costco, Walmart, CVS, and Walgreens are more likely to maintain consistent inventory.

If you're having trouble finding propafenone at your local pharmacy, medfinder can call pharmacies near you to find which ones have your specific prescription in stock — saving you hours on hold.

Who Can Prescribe Propafenone?

Propafenone is not a controlled substance and has no special DEA prescribing requirements. However, because it carries an FDA boxed warning and requires ECG monitoring before and during therapy, the initial prescription is typically issued by a specialist with expertise in cardiac arrhythmias. Long-term maintenance prescriptions may be managed by primary care in some cases.

• Cardiac Electrophysiologists — subspecialists in heart rhythm disorders; highest expertise in propafenone prescribing
• Cardiologists — regularly prescribe propafenone for AF and PSVT management
• Internal Medicine Physicians — may manage stable, established propafenone patients
• Nurse Practitioners and Physician Assistants — can prescribe in cardiology practice settings in most states

Propafenone cannot be initiated via telehealth alone due to ECG monitoring requirements. However, patients already established on propafenone may use telehealth for routine follow-up and refill management with their cardiologist.

Is Propafenone a Controlled Substance?

No. Propafenone is not a controlled substance. It is not classified under any DEA schedule (Schedule I-V). While propafenone is a prescription-only medication due to its cardiac effects and the need for medical monitoring, it does not have abuse potential and is not subject to the additional dispensing restrictions that apply to opioids, stimulants, or other scheduled drugs.

This means patients can receive propafenone prescriptions for up to a 90-day supply, refills are permitted without special restrictions, and prescriptions can be called in or sent electronically to pharmacies without the additional safeguards required for controlled substances. However, propafenone does carry an FDA boxed warning due to its potential proarrhythmic effects, and requires appropriate medical supervision and monitoring during treatment.

Common Side Effects of Propafenone

The following side effects were reported in more than 5% of patients in clinical trials:

• Unusual or metallic taste — most distinctive and common side effect
• Nausea and/or vomiting
• Dizziness
• Constipation
• Headache
• Fatigue
• First-degree AV block (ECG finding, usually asymptomatic)

Serious Side Effects — Seek Medical Attention

• Proarrhythmia — new or worsened ventricular arrhythmias (occurs in ~4.7% of patients)
• Agranulocytosis — severe drop in white blood cells; watch for fever, chills, sore throat
• New or worsened heart failure
• Bronchospasm — wheezing or difficulty breathing; especially in asthma/COPD patients
• Lupus-like syndrome — joint pain, rash, fever (rare)

Final Thoughts on Propafenone

Propafenone (Rythmol) has been a cornerstone of cardiac rhythm management for over 35 years. As a Class IC antiarrhythmic, it is most effective — and safest — in patients with structurally normal hearts who need rhythm control for atrial fibrillation or PSVT. Generic availability and multiple manufacturers make it generally accessible, though patients may occasionally encounter stocking gaps, particularly for the extended-release formulation.

Cost is manageable for most patients, with discount cards reducing the generic IR tablet price to as little as $16-$33. Insurance coverage is generally strong for the immediate-release tablets on most commercial plans and Medicare Part D. The FDA boxed warning deserves respect — this is a medication that requires proper monitoring and should never be stopped abruptly.

If you're struggling to find propafenone at a pharmacy near you, medfinder can help. Enter your medication details and location, and medfinder will call pharmacies near you to find which ones have propafenone in stock — then text you the results so you can fill your prescription without the phone-tree hassle.