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Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.




WARNING: This medication sometimes produces new irregular heartbeats (arrhythmias). Therefore, it should be used in carefully selected patients. Consult your doctor or pharmacist for more information.


This medication is used to treat irregular heart rhythms (arrhythmias) and maintain a normal heart rate.

How To Use

This medication may be taken without regard to meals. This medication works best when there is a constant level of the drug in your body. To do this, take each dose exactly as prescribed at evenly spaced intervals, usually every twelve (12) hours. Try to take each dose at the same time each day. Do not stop taking this medication or change the dose without first consulting your doctor. Some conditions may become worse when the drug is suddenly stopped.

Side Effects

Constipation, loss of appetite, nausea, vomiting, dizziness, headache, skin rash, blurred vision, anxiety, depression or stomach upset may occur as your body adjusts to the medication. If these effects persist or worsen, inform your MD. Because this medication may cause lightheadedness or dizziness in some people, make sure you know how you react to this drug before driving or operating machinery. Notify your doctor if you develop: chest pain, irregular heartbeat, trembling or shaking, shortness of breath, swelling of feet or lower legs. If you notice other effects not listed above, contact your doctor or pharmacist.


Be sure your doctor or dentist knows your complete medical history especially if you are planning to undergo any medical or dental procedures. This medication should be used only when clearly needed during pregnancy. It is not known if this medication appears in breast milk. Consult with your doctor before breast-feeding.

Drug Interactions

Inform your doctor about all the medicines you use (both prescription and nonprescription), especially of: other medicines to treat irregular heartbeats (antiarrhythmics), beta-blockers (e.g., propranolol), cimetidine, digoxin. Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include nausea, vomiting, seizures, slow heartbeat, and fainting.


Your doctor may want you to check your pulse rate every day while you take this medication. Learn how to monitor your pulse. To evaluate the effectiveness of this medication, your doctor may periodically take a blood sample to measure the amount of the drug in your body. Tests such as chest x-ray, eye exams or electrocardiogram (EKG) may also be done. Keep all appointments with your doctor.

Missed Dose

If you miss a dose, take as soon as remembered; do not take if it is almost time for the next dose, instead, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.


Store at room temperature away from sunlight and moisture.

Medical Alert

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