Norpace Side Effects Center

Last updated on RxList: 1/19/2023
Norpace Side Effects Center

What Is Norpace?

Norpace (disopyramide phosphate) is an anti-arrhythmic drug used to treat seriously irregular heartbeat patterns. Norpace is available in generic form.

What Are Side Effects of Norpace?

Norpace may cause serious side effects including:

  • hives,
  • difficulty breathing,
  • swelling of your face, lips, tongue, or throat,
  • new or worsening irregular heartbeat pattern,
  • little or no urinating,
  • painful or difficult urination,
  • lightheadedness,
  • shortness of breath,
  • swelling,
  • rapid weight gain,
  • headache,
  • hunger,
  • weakness,
  • sweating,
  • confusion,
  • irritability,
  • dizziness,
  • fast heart rate, and
  • jitteriness

Get medical help right away, if you have any of the symptoms listed above.

Common side effects of Norpace include dry mouth, constipation, nausea, abdominal pain, gas, bloating, blurred vision, dry nose/eyes/throat, dizziness, tiredness, muscle aches or pains, rash, itching, and urination problems (such as difficulty urinating or unusual frequent urge to urinate).

Seek medical care or call 911 at once if you have the following serious side effects:

  • Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
  • Serious heart symptoms such as fast, irregular, or pounding heartbeats; fluttering in your chest; shortness of breath; and sudden dizziness, lightheadedness, or passing out;
  • Severe headache, confusion, slurred speech, arm or leg weakness, trouble walking, loss of coordination, feeling unsteady, very stiff muscles, high fever, profuse sweating, or tremors.

This document does not contain all possible side effects and others may occur. Check with your physician for additional information about side effects.

Dosage for Norpace

The usual adult dosage of Norpace or Norpace CR is 400 to 800 mg per day given in divided doses.

What Drugs, Substances, or Supplements Interact with Norpace?

Norpace may interact with other anti-arrhythmics, beta-blockers, erythromycin, clarithromycin, phenytoin, phenobarbital, cisapride, rifampin, or warfarin. Tell your doctor all medications you use.

Norpace During Pregnancy and Breastfeeding

During pregnancy, Norpace should be used only when prescribed. Rarely, this drug may cause early labor during pregnancy. Discuss the risks and benefits with your doctor. This medication passes into breast milk, and the effect on a nursing infant is unknown. Consult your doctor before breastfeeding.

Additional Information

Our Norpace (disopyramide phosphate) Side Effects Drug Center provides a comprehensive view of available drug information on the potential side effects when taking this medication.

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.


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Norpace Consumer Information

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.


In the U.S., 1 in every 4 deaths is caused by heart disease. See Answer
Norpace Professional Information


The adverse reactions which were reported in Norpace clinical trials encompass observations in 1,500 patients, including 90 patients studied for at least 4 years. The most serious adverse reactions are hypotension and congestive heart failure. The most common adverse reactions, which are dose dependent, are associated with the anticholinergic properties of the drug. These may be transitory, but may be persistent or can be severe. Urinary retention is the most serious anticholinergic effect.

The following reactions were reported in 10% to 40% of patients:

Anticholinergic: dry mouth (32%), urinary hesitancy (14%), constipation (11%)

The following reactions were reported in 3% to 9% of patients:

Anticholinergic: blurred vision, dry nose/eyes/throat

Genitourinary: urinary retention, urinary frequency and urgency

Gastrointestinal: nausea, pain/bloating/gas

General: dizziness, general fatigue/muscle weakness, headache, malaise, aches/pains

The following reactions were reported in 1% to 3% of patients:

Genitourinary: impotence

Cardiovascular: hypotension with or without congestive heart failure, increased congestive heart failure (see WARNINGS), cardiac conduction disturbances (see WARNINGS), edema/weight gain, shortness of breath, syncope, chest pain

Gastrointestinal: anorexia, diarrhea, vomiting

Dermatologic: generalized rash/dermatoses, itching

Central nervous system: nervousness

Other: hypokalemia, elevated cholesterol/triglycerides

The following reactions were reported in less than 1%:

Depression, insomnia, dysuria, numbness/tingling, elevated liver enzymes, AV block, elevated BUN, elevated creatinine, decreased hemoglobin/hematocrit

Hypoglycemia has been reported in association with Norpace administration (see WARNINGS).

Infrequent occurrences of reversible cholestatic jaundice, fever, and respiratory difficulty have been reported in association with disopyramide therapy, as have rare instances of thrombocytopenia, reversible agranulocytosis, and gynecomastia. Some cases of LE (lupus erythematosus) symptoms have been reported; most cases occurred in patients who had been switched to disopyramide from procainamide following the development of LE symptoms. Rarely, acute psychosis has been reported following Norpace therapy, with prompt return to normal mental status when therapy was stopped. The physician should be aware of these possible reactions and should discontinue Norpace or Norpace CR therapy promptly if they occur.

Read the entire FDA prescribing information for Norpace (Disopyramide Phosphate)


Heart Disease: Symptoms, Signs, and Causes See Slideshow

© Norpace Patient Information is supplied by Cerner Multum, Inc. and Norpace Consumer information is supplied by First Databank, Inc., used under license and subject to their respective copyrights.

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