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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: Rarely, procainamide may cause serious (sometimes fatal) blood disorders (e.g., agranulocytosis, hypoplastic anemia). Notify your doctor immediately if you develop any of the following symptoms: signs of infection (e.g., persistent sore throat or fever), easy bruising or bleeding, or unusual fatigue. This drug may need to be stopped if any of these problems occur. Procainamide must be used only in cases of life-threatening heart arrhythmias. Prolonged procainamide use may result in testing positive (ANA test) for a serious skin problem (lupus erythematosus-like syndrome). Notify your doctor immediately if you develop skin eruptions (swelling or redness).


Procainamide is used to treat an irregular heartbeat (arrhythmia).

How To Use

Take this medication at evenly spaced intervals throughout the day and night. It is important to take each dose at the designated time. Do not increase your dose, take this more often or skip any doses since improper dosing may lead to a worsening of your condition. Ask your doctor or pharmacist to help you plan a correct and convenient dosing schedule. Do not stop taking this medication without consulting your doctor. It is important to continue taking this medication even if you feel well. Sustained-release tablets must be swallowed whole. Do not crush or chew them or the long action can be destroyed and the chance of side effects increased.

Side Effects

Stomach upset, loss of appetite, nausea, diarrhea, bitter taste in mouth, or flushing may occur the first several days as your body adjusts to the medication. If any of these effects continue or worsen, notify your doctor promptly. Notify your doctor if you develop: chest pain, stomach pain, vomiting, hallucinations, depression, fever, chills, mouth sores, sore throat, skin rash, dark urine, muscle aches, joint pain, easy bruising, breathing trouble. Tell your doctor immediately if any of these highly unlikely but very serious side effects occur: dizziness, fainting, irregular heartbeat. This medication can cause blood disorders. Laboratory tests will be done periodically to monitor for these effects. If you notice other effects not listed above, contact your doctor or pharmacist.


Tell your doctor if you have: pre-existing kidney disease, heart disease, liver disease, myasthenia gravis, lupus erythematosus, blood disorders, any allergies (especially to procaine, local anesthetic drugs, or aspirin). A preservative (benzyl alcohol) which may be found in the injection form of this medication or in the liquid used to mix the injection form of this medication (diluent) can infrequently cause serious problems (sometimes death) if given by injection to an infant during the first months of life (neonatal period). The risk is greater with lower birth weight infants and is greater with increased amounts of benzyl alcohol. Symptoms include sudden gasping, low blood pressure, or a very slow heartbeat. Report these symptoms to the doctor immediately should they occur. If possible, a preservative-free product should be used when treating neonates. This medication should be used only if clearly needed during pregnancy. Discuss the risks and benefits with your doctor. Since small amounts of this medication are found in breast milk, consult your doctor before breast-feeding.

Drug Interactions

Tell your doctor of any over-the-counter or prescription medication you may take especially: medication for your heart, beta-blockers, cimetidine, ranitidine, amiodarone, trimethoprim. Report other drugs which affect the heart rhythm (QTc prolongation), such as: dofetilide, pimozide, quinidine, sotalol, sparfloxacin, "water pills" (diuretics such as furosemide or hydrochlorothiazide). Ask your doctor or pharmacist for more details. 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 weakness, fatigue, dizziness, fast heartbeat, confusion, and decreased urination.


Some brands of this medication contain a wax core which slowly releases the drug in the body. This wax core is not digested and may be seen in your stool. Do not be alarmed.

Missed Dose

If you miss a dose, take it as soon as remembered; do not take it if it is near the time for the next dose, instead, 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 (15 to 30 degrees C) away from heat and light. 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).