Procainamide Side Effects, Uses, and Interactions

A man holding his heart
  • Procainamide is an antiarrhythmic drug. These are medications prescribed to help stabilize the rhythm of the heart in patients with arrhythmias.

  • The drug works by affecting the electrical conduction system in the heart to restore a normal heart rhythm.

  • Some common procainamide side effects include nausea, vomiting, lightheadedness, and headaches.

  • More serious side effects of procainamide include blood disorders, gastrointestinal disturbances, and even neurological problems.

Having an irregular heartbeat is known as an arrhythmia. It can disrupt the heart’s ability to pump blood effectively. This can lead to serious and even life-threatening health complications.

In 1950, the Food and Drug Association (FDA) approved procainamide hydrochloride for treating heart rhythm conditions.

Now widely used, procainamide helps to address issues related to an irregular heart rhythm, such as reduced blood flow, impaired oxygen delivery, and increased risk of heart failure.

For decades, procainamide has been very effective in treating arrhythmias in patients of all ages.

If you’re considering taking procainamide, you might wonder what to expect.

What is Procainamide Therapy?

Procainamide is a medication that is used to treat abnormal heart rhythms. It belongs to a class of medicines known as antiarrhythmic drugs.

This medication works to restore a normal heart rhythm in people with heart disorders. It does this by blocking certain electrical signals in the heart, which may help to stabilize irregular rhythms.

The drug is administered in two ways:

  • Oral procainamide: Taken in the form of tablets or capsules

  • Intravenous (IV) procainamide: Administered via an IV drip in hospital settings for more acute cases

Procainamide is only available via a prescription from a doctor.

What is Procainamide Used For?

Procainamide can keep your heart beating normally if you have a heart rhythm disorder.

These disorders occur in the lower chambers of your heart, called the ventricles, which allow blood to flow out of your heart.

According to the National Institutes of Health (NIH), procainamide is a medication used to treat life-threatening ventricular arrhythmias, including:

  • Supraventricular arrhythmias: A disruption in the electrical impulses responsible for heart contractions

  • Atrial flutter: A type of supraventricular arrhythmia that originates in the atria of the heart

  • Atrial fibrillation (AF): Chaotic, rapid, and irregular electrical activity in the ventricles

  • Ventricular tachycardia (VT): A fast heart rate originating in the ventricles

  • Wolf-Parkinson-White (WPW): A fairly rare congenital heart syndrome that occurs when there is an abnormal electrical pathway in the heart

Here are a few of the main reasons why procainamide is so widely used in treating people with arrhythmias are:

  • It’s known to be highly effective in restoring a normal heart rhythm in people with heart disorders.

  • Its safety and effectiveness have been well-established through extensive clinical practice and research.

  • It has a wide range of applications and can be used to treat a variety of heart rhythm conditions.

  • It’s a flexible treatment in that it is available in oral and IV forms, meaning there are various options available based on a patient’s specific needs.

  • The drug is known for significantly improving the quality of life in people who have debilitating arrhythmia.

  • The dosage of the medication is adjustable and healthcare professionals can identify the optimal dose for their patients.

What are the Side Effects of Procainamide?

If you take procainamide hydrochloride, you might experience one or more of the following symptoms:

Nausea and vomiting

It’s possible that procainamide may irritate your stomach lining, which can lead to nausea, vomiting, and abdominal discomfort.


Similar to the above, the irritation of the gastrointestinal tract can result in an upset stomach when taking procainamide.

Loss of appetite

The gastrointestinal discomfort caused by procainamide may reduce your desire to eat.


Procainamide may affect your blood pressure, and it can cause changes to your heart’s rhythm. Both these actions can lead to lightheadedness or dizziness.


Although there’s limited research on why procainamide causes headaches, it’s believed that the way it changes your blood flow and blood pressure may cause this side effect.

Blurred vision

Due to its effect on the nervous system and blood pressure, procainamide may cause blurred or double vision.

A fever or chills

Procainamide can cause changes in white blood cell count, which could lead to infections with symptoms like chills and fever.

A rash

As we will discuss shortly, procainamide has been known to cause lupus-like symptoms in some patients, including a rash.

Muscle or joint pain

This may also be related to the lupus-like side effects of taking procainamide.

Mental depression

In rare cases, procainamide might cause mental changes such as depression and anxiety in some individuals. This may be due to procainamide's neurological effects on the body.

People with underlying mental health conditions may be more at risk of depression and other mood disorders when taking procainamide.

A man staring at the window

Symptoms of Adverse Reactions to Procainamide

Aside from the common symptoms outlined above, there are certain adverse effects that people taking procainamide might experience.

These are more serious side effects and you should report them to a healthcare professional if you experience any of them, as this could indicate a medical emergency.

Blood disorders

As procainamide may decrease the number of white blood cells and platelets in the body, you are at a higher risk of infections and bleeding.

Heart rhythm problems

Procainamide may worsen or cause new heart rhythm problems, even though it is used to treat life-threatening arrhythmias.

Lupus-like symptoms

Patients treated with procainamide might develop symptoms that are similar to what someone with lupus would experience. These symptoms may include joint pain, fever, and a rash on the face.

Neurological effects

Some people may experience side effects related to the nervous system, including confusion and hallucinations.

Gastrointestinal disturbances

Although extremely rare, people taking procainamide may develop pancreatitis or hepatitis.

Signs You are Having a Serious Allergic Reaction to Procainamide

It’s possible that you could experience a serious allergic reaction when taking procainamide. The signs of an allergic reaction associated with this medication include:

  • A sore throat

  • Bruising

  • Unusual tiredness

  • Tenderness and tingling at the injection site

  • Confusion

  • Fever

  • Joint pain or swelling

  • Pain when breathing

  • Sore mouth, gums, or throat

  • Hallucinations

If you are being treated with procainamide and experience any of the above symptoms or a severe allergic reaction, it’s important that you call emergency services or visit your nearest emergency center right away. A severe allergic reaction can be fatal.

What to Tell Your Healthcare Provider Before Taking Procainamide

Before treating you with procainamide, your healthcare provider will record your full medical history to ensure it is safe for you to take the drug.

Ensure you tell your doctor if you:

  • Have or had a kidney disease

  • Have impaired renal function

  • Have preexisting marrow failure

  • Are taking any blood pressure medication

  • Are allergic to or have experienced adverse effects with procainamide, anesthetics, or aspirin

  • Are pregnant, planning to conceive, or breastfeeding

  • Are taking any other medications, including herbal products

Your doctor will run blood tests, called complete blood counts, while you are receiving procainamide therapy to assess the drug’s efficacy and monitor your body’s response to it.

What to Do if You Overdose on Procainamide

A procainamide overdose can have serious and even life-threatening consequences.

If you believe you have overdosed on procainamide or you experience any of the side effects listed below, call 911 and seek emergency medical attention.

Signs of procainamide toxicity include:

  • Cardiac arrhythmias

  • Decrease in urination

  • Dizziness (severe)

  • Fainting or drowsiness

  • Seizures

  • Vision disturbances

  • Chest pain

Potential Drug Interactions with Procainamide

An interaction means that some drugs may interfere with how procainamide works. Some of these medications include:

  • Other antiarrhythmic drugs

  • Neuromuscular blocking agents such as succinylcholine

  • Cimetidine

  • Digoxin

It’s worth noting that consuming alcohol may interrupt the mechanism of procainamide. Speak to your doctor about how much alcohol is safe to drink while taking procainamide.

Brand Names for Procainamide

Procainamide is an ingredient in the following brand-name drugs:

  • Procanbid

  • Procan SR

  • Pronestyl

  • Pronestyl-SR

Precautions to Take for IV and Oral Procainamide

If you are receiving IV procainamide, there are certain precautions you should take to ensure you are safe. This will typically be done in a clinical setting, so doctors and other healthcare staff will be there to help you.

Check-in with your doctor regularly

It’s important to have regular consultations with your doctor so that they can monitor your progress and any side effects you may experience after your IV treatment.

Being completely open and honest with your healthcare provider is vital to ensure the medication works as it should and to reduce possible side effects.

Use extra care to avoid falling

Elderly patients who receive large doses of procainamide should take extra care to avoid falling. This is especially true if they are experiencing dizziness or lightheadedness as a side effect.

Avoid dangerous activities

Before driving or using heavy machinery, first see how your body reacts to this medication. Avoid physically demanding activities if you feel dizzy or less alert than usual.

Stay hydrated

Dehydration may increase your risk of developing side effects while taking procainamide. Ensure that you stay adequately hydrated and be cautious in hot weather and when engaging in activities that cause sweating.

An old woman drinking water

Who Should Not Take Procainamide?

Certain individuals should not be prescribed procainamide, including people with:

  • Previous allergic reactions: Those with a known allergy to procainamide or any other ingredients in the oral medication.

  • Myasthenia gravis: Procainamide may exacerbate symptoms of this neurotransmitter disorder that causes muscle weakness.

  • Complete heart block: In this condition where electrical signals in the heart are significantly disrupted, procainamide might worsen the block.

  • Low white blood cell count: A history of low white blood cell counts or bone marrow disorders may mean you need to use procainamide with caution as it can further reduce white blood cell counts.

  • Kidney or liver disease: Impaired liver or kidney function may be worsened when taking procainamide as this medication is metabolized by these organs.

  • Lupus: A history of systemic lupus erythematosus (SLE) or other autoimmune diseases may mean procainamide isn’t the right medication for you.

Where Can I Learn More About Procainamide?

LifeMD can connect you to a licensed medical professional who can answer any questions you have about this drug and can prescribe procainamide treatment if necessary.

Make your appointment today to learn more about procainamide.

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This article is intended for informational purposes only and should not be considered medical advice. Consult a healthcare professional or call a doctor in the case of a medical emergency.

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