Pronestyl Side Effects Center

Last updated on RxList: 4/8/2009
Pronestyl Side Effects Center

Last reviewed on RxList 12/2/2015

Pronestyl (procainamide hydrochloride) is a cardiac antiarrhythmic drug used to help keep the heart beating normally in people with certain heart rhythm disorders of the ventricles (the lower chambers of the heart that allow blood to flow out of the heart). The brand name Pronestyl is discontinued in the U.S. Generic versions may be available. Common side effects of Pronestyl (procainamide hydrochloride) include nausea, vomiting, loss of appetite, diarrhea, bitter taste in the mouth, dizziness, tired feeling, flushing (warmth, redness, or tingly feeling), and itching or rash.

The initial dose of procainamide for younger adult patients with normal renal function is up to 50 mg/kg of body weight per day taken orally in divided doses every three hours. Procainamide may interact with cimetidine, digoxin, or heart rhythm medications. Tell your doctor all medications you use. During pregnancy, procainamide should be used only when prescribed. This medication passes into breast milk and may have undesirable effects on a nursing infant. Consult your doctor before breastfeeding.

Our Pronestyl (procainamide hydrochloride) 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.


Heart Disease: Symptoms, Signs, and Causes See Slideshow
Pronestyl Consumer Information

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

Tell your medical caregivers right away if you have:

  • sudden fever, chills, sore throat, mouth sores, weakness;
  • joint pain, muscle pain or weakness;
  • wheezing, chest pain;
  • easy bruising, pale or yellowed skin, dark colored urine;
  • depression, dizziness, hallucinations;
  • stomach pain, nausea, vomiting, diarrhea, loss of appetite; or
  • lupus-like symptoms--joint pain or swelling, stomach pain, chest pain, shortness of breath, and a rash or patchy skin color that worsens in sunlight.

Common side effects may include:

  • stomach pain, loss of appetite, nausea, vomiting, diarrhea;
  • dizziness, weakness, depressed mood;
  • abnormal liver function tests; or
  • rash or itching.

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
Pronestyl Professional Information



Hypotension following oral PA administration is rare. Hypotension and serious disturbances of cardiorhythm such as ventricular asystole or fibrillation are more common after (see OVERDOSAGE, WARNINGS). Second degree heart block has been reported in 2 of almost 500 patients taking PA orally.


A lupus erythematosus-like syndrome of arthralgia, pleural or abdominal pain, and some-times arthritis, pleural effusion, pericarditis, fever, chills, myalgia, and possibly related hematologic or skin lesions (see below) is fairly common after prolonged PA administration, perhaps more often in patients who are slow acetylators (see Boxed WARNINGS and PRECAUTIONS). While some series have reported less than 1 in 500, others have reported the syndrome in up to 30 percent of patients on long term oral PA therapy. If discontinuation of PA does not reverse the lupoid symptoms, corticosteroid treatment may be effective.


Neutropenia, thrombocytopenia, or hemolytic anemia may rarely be encountered. Agranulocytosis has occurred after repeated use of PA, and deaths have been reported. (See Boxed WARNING, WARNINGS section.)


Angioneurotic edema, urticaria, pruritus, flushing, and maculopapular rash have also occurred occasionally.


Anorexia, nausea, vomiting, abdominal pain, bitter taste, or diarrhea may occur in 3 to 4 percent of patients taking oral procainamide.

Elevated Liver Enzymes

Elevations of transaminase with and without elevations of alkaline phosphatase and bilirubin have been reported. Some patients have had clinical symptoms (e.g., malaise, right upper quadrant pain). Deaths from liver failure have been reported.

Nervous System

Dizziness or giddiness, weakness, mental depression, and psychosis with hallucinations have been reported occasionally.

Read the entire FDA prescribing information for Pronestyl (Procainamide)


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

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