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Drug Profile

The information on this site is intended to supplement and enhance, not replace, the advice of a physician who is familiar with your medical history. Decisions about your health should always be made ONLY after detailed conversation with your doctor.

Limited Use [what does this mean?]
Generic drug name: procainamide (proe KANE a mide)
GENERIC: available FAMILY: Drugs for Abnormal Heart Rhythm
Find the drug label by searching at DailyMed.

Pregnancy and Breast-feeding Warnings [top]

Pregnancy Warning

Animal studies were not done. However, because of the potential for serious adverse effects to the fetus (see boxes below), procainamide should not be used by pregnant women.

Breast-feeding Warning

Procainamide is excreted in human milk and absorbed by the nursing infant. Because of the potential for serious adverse effects in nursing infants, you should not take this drug while nursing.

Safety Warnings For This Drug [top]


In the National Heart, Lung, and Blood Institute’s Cardiac Arrhythmia Suppression Trial (CAST) (a long-term, multicentered, randomized, double-blind study), in patients with asymptomatic non-life-threatening ventricular (the large chambers of the heart) arrhythmias (rhythm disturbances) who had a heart attack more than six days but less than two years previous, deaths or nonfatal cardiac arrest were seen in 7.7% of those patients treated with encainide or flecainide, members of the Class 1 group of antiarrhythmic drugs, compared to 3.0% in patients receiving an inactive sugar pill or placebo.

Because of the known ability of the Class 1 drugs, such as quinidine, to cause rhythm disturbances, and the lack of evidence of improved survival for any antiarrhythmic drug in patients without life-threatening heart rhythm disturbances, the use of the Class 1 drugs should be reserved for patients with life-threatening rhythm disturbances of the ventricles. These warnings now appear in the FDA-approved product labeling, or package insert, for all Class 1 drugs, including: disopyramide (NORPACE and generics), flecainide (TAMBOCOR), mexiletine (MEXITIL and generics), moricizine (ETHMOZINE), procainamide (PROCANBID and generics), propafenone (RYTHMOL), quinidine (DURAQUIN, QUINAGLUTE DURA-TABS, QUINIDEX, and generics), and tocainide (TONOCARD).


Positive ANA Titer: The prolonged administration of procainamide often leads to the development of a positive antinuclear antibody (ANA) test, with or without symptoms of lupus erythematosus–like syndrome. If a positive ANA titer develops, the benefits versus risks of continued procainamide therapy should be assessed.



Agranulocytosis, bone marrow depression, neutropenia, hypoplastic anemia, and thrombocytopenia have been reported in patients receiving procainamide hydrochloride at a rate of approximately 0.5%. Most patients received procainamide hydrochloride within the recommended dosage range. Fatalities have occurred (with approximately 20–25% mortality in reported cases of agranulocytosis). Since most of these events have been noted during the first 12 weeks of therapy, it is recommended that complete blood counts, including white cell, differential, and platelet counts, be performed at weekly intervals for the first 3 months of therapy, and periodically thereafter. Complete blood counts should be performed promptly if the patient develops any signs of infection (such as fever, chills, sore throat, or stomatitis), bruising, or bleeding. If any of these hematologic disorders are identified, procainamide hydrochloride should be discontinued. Blood counts usually return to normal within 1 month of discontinuation. Caution should be used in patients with preexisting marrow failure or cytopenia of any type.


When this drug was used to treat rhythm disturbances of the small chambers of the heart (atria), it provided no survival advantage and a higher risk of serious adverse effects than older drugs such as digoxin, the beta-blockers, and the calcium channel blockers diltiazem and verapamil.[1],[2]

This drug is not approved by the FDA to treat rhythm disturbances of the atria.

Facts About This Drug [top]

Procainamide slows the heart rate and stabilizes irregular heartbeats (arrhythmias) of the large chambers of the heart (ventricles). Since this drug frequently causes a disease called lupus erythematosus, as well as other adverse effects, it is not the best choice for long-term treatment of irregular heartbeats. If your kidney or liver function is impaired, you should be taking less than the usual dose.[3]


Many people who are taking procainamide or another drug in its family have...

Procainamide slows the heart rate and stabilizes irregular heartbeats (arrhythmias) of the large chambers of the heart (ventricles). Since this drug frequently causes a disease called lupus erythematosus, as well as other adverse effects, it is not the best choice for long-term treatment of irregular heartbeats. If your kidney or liver function is impaired, you should be taking less than the usual dose.[3]


Many people who are taking procainamide or another drug in its family have relatively mild disturbances in their heart rhythm and no symptoms of underlying heart disease. The vast majority of these people do not need these drugs, and there is no evidence that using them improves health. In fact, most of the drugs in this family have severe adverse effects that are sometimes worse and even more life-threatening than the irregular heartbeats they treat. All of these drugs can also cause new irregularities in your heartbeat.


If you have an irregular heartbeat without any symptoms of underlying heart disease, you should not be exposed to the dangers of a drug that has no health benefit for your condition.[4] If you are taking procainamide or another drug in its family for an irregular heartbeat (arrhythmia), talk to your doctor and find out whether you also have symptoms of underlying heart disease. If not, discuss the possibility of stopping the drug.


Since there is a narrow range between a helpful and a harmful amount of this drug in your body, call your doctor immediately if you experience adverse effects (see Adverse Effects).

Before You Use This Drug [top]

Do not use if you have or have had:

  • complete heart block
  • digitalis toxicity with heart block
  • a particular heart arrhythmia called Torsades de pointes

Tell your doctor if you have or have had:

  • allergies to drugs
  • asthma or emphysema
  • digitalis toxicity
  • incomplete heart block or other heart problems
  • kidney or liver problems
  • lupus erythematosus
  • myasthenia gravis
  • pregnancy or are breast feeding

Tell your doctor about any other drugs you take, including aspirin, herbs, vitamins, and other nonprescription products.

When You Use This Drug [top]

  • Until you know how you react to this drug, do not drive or perform other activities requiring alertness. Procainamide may cause dizziness.
  • Do not stop taking this drug suddenly. Your doctor must give you a schedule to lower your dose gradually, to prevent serious changes in heart function.
  • Wear a medical identification bracelet or carry a card stating that you take procainamide.
  • If you plan to have any surgery, including dental, tell your doctor that you take this drug.

How to Use This Drug [top]

  • If you miss a dose, take it as soon as you remember, but skip it if it is less than two hours until your next scheduled dose. Do not take double doses.
  • Do not share your medication with others.
  • Take the drug at the same time(s) each day.
  • Take with food or milk.
  • Swallow extended-release tablets whole. Do not crush or break them.
  • Store at room temperature with the lid on tightly. Do not store in the bathroom. Do not expose to heat, moisture, or strong light. Keep out of reach of children.

Interactions with Other Drugs [top]

The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drug’s FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:

amiodarone, AVELOX, BETAPACE, cimetidine, CORDARONE, cyclosporine, GLUCOVANCE, halofantrine, metformin, mizolastine, moxifloxacin, NEORAL, ORAP, pimozide, sotalol, SANDIMMUNE, sparfloxacin, TAGAMET, ZAGAM, zotepine.

Adverse Effects [top]

Call your doctor immediately if you experience:

  • signs of lupuslike syndrome: fever, chills, joint pain or swelling, pain with breathing, skin rash or itching
  • hallucinations
  • depression
  • sore mouth, gums, or throat
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Call your doctor if these symptoms continue:

  • diarrhea
  • loss of appetite
  • dizziness or lightheadedness

Signs of overdose:

  • confusion, dizziness, fainting
  • drowsiness
  • nausea and vomiting
  • unusual decrease in urination
  • unusually fast or irregular heartbeat

If you suspect an overdose, call this number to contact your poison control center: (800) 222-1222.

Periodic Tests[top]

Ask your doctor which of these tests should be done periodically while you are taking this drug:

  • complete blood count
  • heart function tests, such as electrocardiogram (ECG, EKG)
  • blood pressure
  • liver function tests
  • blood levels of procainamide and NAPA (a metabolite of procainamide)
  • antinuclear antibody test (if this is positive, ask your doctor about changing your drug, since a positive value is often linked with a lupuslike syndrome)


last reviewed December 31, 2023