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Disopyramide phosphate oral

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).

How To Use

This is best taken with a full glass of water on an empty stomach one hour before or two hours after meals. If stomach upset occurs, it may be taken with food. Sustained-release tablets and capsules must be swallowed whole. Do not crush or chew them. This medication works best when there is a constant level of the drug in your body. To do this, take each dose as prescribed at evenly spaced intervals throughout the day and night. Try to take each dose at the same time each day. Do not stop taking this medication without consulting your doctor. Some conditions may worsen if the drug is stopped suddenly.

Side Effects

Blurred vision, dry mouth, constipation, difficulty urinating or dizziness may occur. If any of these effects persist or worsen, contact your doctor. Inform your doctor if you develop: chest pain, rapid heartbeat, confusion, easy bruising or bleeding, breathing difficulties, rash. If you notice other effects not listed above, contact your doctor or pharmacist.


Tell your doctor your medical history, especially: muscle problems (myasthenia gravis), high blood pressure, glaucoma (or a family history of glaucoma), heart disease, liver disease, kidney disease, prostate or urinating problems, any allergies. Because this drug may cause dizziness, use caution performing activities requiring alertness (e.g., driving) and limit alcohol consumption. This medication should be used only when clearly needed during pregnancy. Discuss the risks and benefits with your doctor. Disopyramide is excreted into breast milk. Though there have been no reports to date of harm to nursing infants, consult your doctor before breast-feeding.

Drug Interactions

Before you take this drug, tell your doctor of any over-the-counter or prescription drugs you are taking, especially: phenobarbital, phenytoin, procainamide, propranolol, quinidine, warfarin, rifampin, macrolide antibiotics (e.g., clarithromycin, erythromycin), quinolone antibiotics (e.g., gatifloxacin, moxifloxacin), cisapride, mizolastine. 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 include unconsciousness, low blood pressure, seizures, and change in heart rhythm.


Your doctor may want you to take your pulse each 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. Do not allow anyone else to take this medication.

Missed Dose

If you miss a dose, take as soon as remembered unless the next scheduled dose is within 4 hours. If so, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.


Store at room temperature between 59 and 86 degrees F (between 15 and 30 degrees C) away from moisture and sunlight. Do not store in the bathroom.

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).