Disopyramide

Disopyramide is an antiarrhythmic medication used for the treatment of ventricular arrhythmias.

• Disopyramide is available under the following different brand names: Norpace, Norpace CR

Common side effects of Disopyramide 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.

Serious side effects of Disopyramide include:

• hives,
• difficulty breathing,
• swelling of the face, lips, tongue, or throat,
• 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).

Rare side effects of Disopyramide include:

• none

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

• 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;
• Serious eye symptoms such as sudden vision loss, blurred vision, tunnel vision, eye pain or swelling, or seeing halos around lights;
• Serious heart symptoms include fast, irregular, or pounding heartbeats; fluttering in the chest; shortness of breath; sudden dizziness, lightheadedness, or passing out. 

This is not a complete list of side effects and other serious side effects or health problems that may occur because of the use of this drug. Call your doctor for medical advice about serious side effects or adverse reactions. You may report side effects or health problems to FDA at 1-800-FDA-1088.

Adult and pediatric dosage

Capsule

• 100 mg
• 150 mg

Capsule, controlled-release

• 100 mg
• 150 mg

Ventricular Arrhythmias

Adult dosage

• Weight above 50 kg
  • Immediate-release: 150 mg orally every 6 hours
  • Controlled-release: 300 mg orally every 12 hours
  • Range: 400-800 mg/day
• Weight above 50 kg
  • Immediate-release: 100 mg orally every 6 hours
  • Controlled-release: 200 mg orally every 12 hours

Rapid Control of Ventricular Arrhythmias

Adult dosage

• Weight above 50 kg
  • Immediate-release: 300 mg orally initially, THEN 150-300 mg every 6 hours
  • If no response within 6 hours, give 200 mg orally every 6 hours; may increase to 250-300 mg every 6 hours if no response in 48 hours
• Weight below 50 kg
  • Immediate-release: 200 mg orally initially, THEN 150-300 mg every 6 hours
  • CR should not be used initially for rapid control

Dosage Considerations – Should be Given as Follows: 

• See “Dosages”

If your medical doctor is using this medicine to treat your pain, 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, health care provider, or pharmacist first.

• Disopyramide has severe interactions with at least 52 other drugs.
• Disopyramide has serious interactions with at least 115 other drugs.
• Disopyramide has moderate interactions with at least 133 other drugs.
• Disopyramide has minor interactions with at least 50 other drugs.

This information does not contain all possible interactions or adverse effects. Visit the RxList Drug Interaction Checker for any drug interactions. Therefore, before using this product, tell your doctor or pharmacist about all your products. Keep a list of all your medications with you and share this information with your doctor and pharmacist. Check with your healthcare professional or doctor for additional medical advice, or if you have health questions or concerns.

Contraindications

• Hypersensitivity
• Cardiogenic shock, preexisting second or third degree heart block, congenital QT syndrome, sick sinus syndrome

Effects of drug abuse

• None

Short-Term Effects

• See “What Are Side Effects Associated with Using Disopyramide?”

Long-Term Effects

• See “What Are Side Effects Associated with Using Disopyramide?”

Cautions

• CHF, ECG abnormalities, electrolyte abnormalities (hypo/hyper K), glaucoma, hypoglycemia, myasthenia gravis, sick sinus syndrome, BPH/urinary retention, need normal potassium prior to use, hypotension, cardiac myopathies, heart failure, prostatic enlargement, Wolff-Parkinson-White syndrome, bundle branch block, hepatic/renal impairment
• Hypotension may occur
• May cause QTc prolongation and subsequent torsade de pointes
• Can both precipitate and exacerbate HF due to marked myocardial depressant effects in HF

Pregnancy and Lactation

• Use with caution if benefits outweigh risks during pregnancy
• Lactation
  • Crosses into breast milk, discontinue drug or do not nurse