Propafenone (Rythmol) is a Class 1C antiarrhythmic medication used to treat certain heart rhythm problems, like atrial fibrillation (AFib). But it's not a good choice for people who have structural heart disease, like heart valve issues. Propafenone (Rythmol) is taken by mouth, typically 2 to 3 times a day, depending on whether you're taking the immediate-release (IR) tablets and extended-release (ER) capsules. Some side effects of propafenone (Rythmol) include dizziness, chest pain, and trouble catching your breath.
Propafenone (Rythmol) is an antiarrhythmic. It works by blocking sodium channels, which play a major part in your heart's electrical activity. It slows down abnormal electrical activity in your heart to treat abnormal rhythms.
| Common Brands | Rythmol SR |
|---|---|
| Drug Class | Antiarrhythmic |
| Controlled Substance Classification | Not a controlled medication |
| Generic Status | Lower-cost generic available |
| Availability | Prescription only |
The following side effects may get better over time as your body gets used to the medication. Let your healthcare provider know immediately if you continue to experience these symptoms or if they worsen over time.
Contact your healthcare provider immediately if you experience any of the following.
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
Less common
fast, irregular, or slow heartbeat
lightheadedness, dizziness, or fainting
shortness of breath
swelling of the feet or lower legs
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
More common
Change in taste or bitter or metallic taste
Less common
Blurred vision
dryness of the mouth
headache
nausea or vomiting
skin rash
unusual tiredness or weakness
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
Propafenone (Rythmol) can cause some serious health issues. This risk may be even higher for certain groups. If this worries you, talk to your doctor or pharmacist about other options.
If you have ventricular arrhythmias, your provider will only prescribe propafenone (Rythmol) if they think your condition is life-threatening. Studies of a medication similar to propafenone (Rythmol) suggest that though rare, taking propafenone (Rythmol) might raise the risk of death, especially for people who've had recent heart attacks. If you're concerned about the risks of taking propafenone (Rythmol), talk with your heart specialist.
Propafenone (Rythmol) can cause worsening of abnormal heart rhythms, including rhythms that are too fast (such as ventricular tachycardia or fibrillation) or too slow (such as as 'heart block' or a very slow heart rate). Many of these conditions are life-threatening, so it's important that you follow-up with your provider regularly. Your provider will check your heart rhythm with an electrocardiogram (EKG) before and after you start propafenone (Rythmol) to make sure the medication is working as it should. If you notice an abnormally slow or fast pulse, chest pain or discomfort, weakness, dizziness, or fainting while taking propafenone (Rythmol), get medical help right away.
Many medications can raise levels of propafenone (Rythmol) in the blood by slowing its breakdown in the liver. When propafenone (Rythmol) levels are too high, you have a greater risk of side effects. Other medications can interact with propafenone (Rythmol) directly and lead to life-threatening abnormal heart rhythms. Be sure to talk to your providers, including your pharmacist, about all the medications you are taking. Don't drink grapefruit juice while taking propafenone (Rythmol). If you smoke tobacco, talk to your provider before starting this medication.
Propafenone (Rythmol) can cause new or worsening heart failure. Contact your provider right away if you notice symptoms of heart failure such as unexplained weight gain, edema (swelling due to more fluid) in legs or feet, or more shortness of breath especially when you lie down.
Taking propafenone (Rythmol) can affect the function of heart devices like defibrillators or pacemakers. Make sure that you get regular checkups to make sure your device is adjusted appropriately while you are on propafenone (Rythmol).
Propafenone (Rythmol) can cause dangerously low white blood cell counts. This usually happens within the first 2 months of therapy, and goes away after you stop taking propafenone (Rythmol). White blood cells are important for your immune system, so you have a higher risk of infection if the counts are low. Call your provider right away if you notice signs of infection like fever, chills, or sore throat.
Poor liver or kidney function can cause propafenone (Rythmol) to accumulate (build up) in the body, leading to more side effects. If you have liver or kidney problems, your provider might check lab and heart tests more frequently to be safe.
If you have myasthenia gravis, taking propafenone (Rythmol) can make your condition worse. It's always best to check with your provider before starting any new medications.
Propafenone (Rythmol) can cause lower sperm counts. This effect usually goes away after you stop taking propafenone (Rythmol). If you hope to have children, speak with your provider about alternative medications for your condition.
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Contraindications are specific health conditions or situations in which a person should not take a medication due to safety concerns. If you have any of the following conditions or if any of the following apply to you, let your healthcare provider know because Propafenone (Rythmol) will not be safe for you to take.
Prescription savings
Stop paying too much for your prescriptions. Compare prices, get pharmacy coupons, and save up to 80%.
Find expert answers to your health questions so you can make the best decisions for yourself and your family.Health conditions
Medications & treatment
Access & affordability
Our monthly healthcare membership can help you save thousands on your prescription costs.Resources
Based on the half-life of Propafenone, it generally takes about 10 to 50 hours for most of Propafenone to leave your system. But some people break the medication down more slowly because of their genetics. If you're in this group, it's possible for it to take about a week for your body to clear the medication.
Although not common, people who took Propafenone have reported both high and low blood pressure as side effects. Changes in blood pressure, especially low blood pressure, is more likely for people who take a higher-than-recommended dose of Propafenone. To keep track of changes in your blood pressure, you can measure your blood pressure at home. Let your provider if you have more questions about how Propafenone might impact your blood pressure.
Propafenone can lower your heart rate or even cause 'heart block,' which can be dangerous. If you have a low heart rate to begin with, your provider or heart specialist will help you decide if this medication is safe to take. When you take Propafenone, your provider might ask you to keep track of your heart rate regularly. If you experience an abnormally low heart rate or rhythm while on Propafenone, your provider might lower your dose or have you try a different medication. Let your provider know right away if you experience symptoms of low heart rate, such as dizziness, chest pain, trouble breathing, or fainting.
Don't stop taking Propafenone unless your provider has specifically told you to stop (like if you're having serious side effects). Take this medication exactly as prescribed, and try not to skip doses. Stopping Propafenone can cause you to have arrhythmias (abnormal heart rhythms), including the arrhythmias that this medication was intended to treat or prevent.
Propafenone doesn't belong to the class of medications called beta blockers. But Propafenone can cause similar side effects as beta-blockers, such as slowing your heart rate or lowering your blood pressure. Some beta blockers, such as sotalol (Betapace), are also approved to treat arrhythmias. Talk to your provider if you have questions about which medication might be more appropriate for your heart condition.
Propafenone interacts with many medications. Some other medications can block the proteins in your body that break down Propafenone. This could lead to higher amounts of Propafenone in your body, which could cause dangerous heart problems. Some examples include paroxetine (Paxil), ritonavir (Norvir), and ketoconazole. You should also avoid drinking grapefruit juice, as it can raise the amount of Propafenone in your body. On the other hand, Propafenone can raise the amounts of other medications in your body, like digoxin (Lanoxin) and warfarin (Coumadin). Make sure to tell your pharmacist or provider all of the medications you're taking so they can screen for interactions.
Weight gain isn't a typical side effect of Propafenone. But in rare cases, this medication can cause or worsen heart failure. People with heart failure can experience build-up of fluid in the body, which can result in weight gain. If you notice a sudden change in your weight, especially if you also have trouble breathing, talk to your provider right away.
