Propafenone

This medication is used to help prevent certain types of serious (possibly fatal) irregular heartbeat (such as paroxysmal supraventricular tachycardia and atrial fibrillation). It is used to help maintain a regular, steady heartbeat. Propafenone is known as an anti-arrhythmic drug. It works by blocking the activity of certain electrical signals in the heart that can cause an irregular heartbeat. Treating an irregular heartbeat can decrease the risk for blood clots, and this effect can reduce your risk of heart attack or stroke.

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

Take this medication by mouth with or without food, usually every 12 hours or as directed by your doctor. Swallow the capsules whole. Do not crush or chew the capsules. Doing so can release all of the drug at once, increasing the risk of side effects. Dosage is based on your medical condition and response to treatment. Use this medication regularly to get the most benefit from it. To help you remember, take it at the same times each day. Tell your doctor if your condition does not improve or if it worsens.

Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor or pharmacist first. Many drugs besides propafenone may affect the heart rhythm (QT prolongation), including amiodarone, dofetilide, flecainide, pimozide, procainamide, quinidine, sotalol, macrolide antibiotics (such as erythromycin), and certain quinolone antibiotics (such as sparfloxacin), among others. (See also Precautions section.) Other medications can affect the removal of propafenone from your body, which may affect how propafenone works. Examples include desipramine, ketoconazole, orlistat, phenobarbital, phenytoin, rifampin, and ritonavir, among others. Propafenone can slow down the removal of other medications from your body, which may affect how they work. Examples of affected drugs include cyclosporine, digoxin, imipramine, metoprolol, propranolol, theophylline, venlafaxine, warfarin, among others. This document does not contain all possible interactions. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share the list with your doctor and pharmacist.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-800-854-1166 (USA) or 1-800-668-1507 (Canada).

Do not share this medication with others. Laboratory and/or medical tests (such as EKG) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

If overdose is suspected, contact your local poison control center or emergency room immediately. US residents can call the US National Poison Hotline at 1-800-222-1222. Canada residents can call a provincial poison control center. Symptoms of overdose may include: severe dizziness, very slow heartbeat, new irregular heartbeat, fainting.

Before taking propafenone, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this medication, tell your doctor or pharmacist your medical history, especially of: breathing problems (such as asthma, chronic bronchitis, emphysema), kidney problems, liver problems, myasthenia gravis. Propafenone may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that require immediate medical attention. The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may affect the heart rhythm (see also Drug Interactions section). Before using propafenone, tell your doctor or pharmacist if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG, previous heart attack), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death). Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using propafenone safely. This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages. Before having surgery, tell your doctor or dentist that you are using this medication. During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor. This medication passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breast-feeding.

Store at room temperature at 77 degrees F (25 degrees C) away from light and moisture. Brief storage between 59-86 degrees F (15-30 degrees C) is permitted. Do not store in the bathroom. Keep all medicines away from children and pets. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

See also Warning section. Dizziness, headache, metallic/salty taste in the mouth, nausea/vomiting, constipation, anxiety, and tiredness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Tell your doctor immediately if any of these rare but very serious side effects occur: signs of infection (such as high fever, severe chills, weakness, persistent sore throat), signs of liver problems (such as persistent nausea/vomiting, stomach/abdominal pain, yellowing eyes/skin, dark urine), worsening symptoms of heart failure (such as ankle/leg swelling, increased tiredness, increased shortness of breath when lying down). Seek immediate medical attention if any of these rare but serious side effects occur: fainting, faster/more irregular heartbeat, severe dizziness. A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Though this medication often gives great benefits to people with irregular heartbeat, it may infrequently cause a serious new irregular heartbeat. Talk with your doctor about the benefits and risks of taking this medication.