Propafenone can help people with atrial fibrillation and some other abnormal heart rhythms. It can give you more time between symptoms. You usually take it three times a day. You may take your first doses in the hospital so healthcare providers can monitor you.
Propafenone comes in tablet or capsule form. The prescription label tells you how many tablets to take each time you take your medication. Take only that amount. You can take propafenone with or without food. If you have any questions about propafenone or refilling your prescription, ask your pharmacist.
Propafenone helps people who have irregular heartbeats (arrhythmias). It affects your heart muscle to keep your heart beating normally. It can help you if you have supraventricular tachycardia (a fast heart rhythm that starts in your heart’s upper chambers). This drug may help you if you have:
In some cases, propafenone can be helpful for abnormal heart rhythms that start in your heart’s lower chambers (ventricular arrhythmias).
The propafenone dosage is 450 to 900 milligrams (mg) per day, split into three doses. People usually take it three times a day. There’s also a sustained release form of this medication that you take twice a day instead of three times a day. You should clarify with your cardiologist whether you’re taking the sustained release form or not.
You may start taking this medication in the hospital so your healthcare team can closely watch how the medication affects you.
It’s important to carefully follow the instructions on the prescription label. Ask your pharmacist or healthcare provider to explain anything about the medication that you don’t understand. Take the medication exactly as your provider tells you to.
You have about 50% of your dose left in your body five to seven hours after taking it. You’ll need to keep a steady level of propafenone in your body. Take the medication at the same times each day. Never stop taking this drug without first talking with your provider. If you suddenly stop taking propafenone, your heartbeat may become irregular.
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Propafenone can help you have more time between symptoms of atrial fibrillation and PSVT.
Propafenone side effects — which aren’t common — may include:
Call your provider if the above symptoms continue or are severe.
If you have dizziness or drowsiness, get up slowly after you’ve been sitting or lying down. Use extra caution when driving or performing activities that require you to be alert until you know how propafenone affects you.
Care for yourself in these ways:
If you have excessive drowsiness, slow heartbeat or irregular heartbeat, immediately stop taking propafenone and call your provider.
Call your provider right away if you have:
Foods and salt substitutes that contain potassium can affect the way propafenone works in your body. Ask your provider about changes you may need to make to what you eat.
Take the missed dose if you remember it within four hours. If four or more hours pass after your scheduled dose, skip the missed dose and take your next regular dose. Don’t take a double dose of propafenone.
Before you start taking propafenone, tell your provider:
If you need to have surgery, including surgery in your mouth, tell your surgeon that you take propafenone.
A note from Cleveland Clinic
Having an abnormal heart rhythm is unsettling. For specific kinds of heart rhythm issues, propafenone can help. When taking this medicine, do yourself a favor and ask your healthcare provider or pharmacist about anything that isn’t clear. Being informed about side effects that can happen may help you avoid unwelcome surprises later.
Last reviewed by a Cleveland Clinic medical professional on 08/09/2023.
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