Disopyramide affects the way that your heart beats.

Disopyramide is used to treat life-threatening irregular heartbeat patterns.

Disopyramide may also be used for purposes not listed in this medication guide.

You should not use disopyramide if you are allergic to it, or if you have:

• long QT syndrome; or
• a serious heart condition such as "AV block" (unless you have a pacemaker).

Do not use disopyramide to treat any heart rhythm disorder that has not been checked and diagnosed by your doctor.

To make sure disopyramide is safe for you, tell your doctor if you have:

• other heart rhythm disorders ("sick sinus syndrome", bundle branch block, Wolff-Parkinson-White syndrome);
• congestive heart failure, or if you have recently had a heart attack;
• low blood pressure;
• low potassium levels in your blood (hypokalemia);
• low blood sugar, or diabetes;
• liver or kidney disease;
• enlarged prostate, bladder obstruction or other urination problems;
• glaucoma;
• myasthenia gravis; or
• if you are malnourished.

FDA pregnancy category C. It is not known whether disopyramide will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant while using this medicine.

Disopyramide can pass into breast milk and may harm a nursing baby. You should not breast-feed while using this medicine.

Use Norpace CR (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have:

• a new or a worsening irregular heartbeat pattern;
• little or no urinating, painful or difficult urination;
• a light-headed feeling, like you might pass out;
• shortness of breath (even with mild exertion), swelling, rapid weight gain; or
• low blood sugar (headache, hunger, weakness, sweating, confusion, irritability, dizziness, fast heart rate, or feeling jittery).

Serious side effects such as heart failure or kidney problems may be more likely in older adults.

Common side effects may include:

• dry mouth, nose, or throat;
• nausea, stomach pain, bloating;
• constipation;
• dry eyes, blurred vision;
• headache, tiredness, general ill feeling; or
• muscle pain or weakness.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

This medicine may cause blurred vision and may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert and able to see clearly.

Drinking alcohol can increase certain side effects of disopyramide.