Medically reviewed by Drugs.com. Last updated on Apr 16, 2022.
WarningThe prolonged administration of procainamide often leads to the development of a positive anti-nuclear antibody (ANA) test, with or without symptoms of a lupus erythematosus-like syndrome. If a positive ANA titer develops, the benefit versus risks of continued procainamide therapy should be assessed.MortalityIn the National Heart, Lung, and Blood Institute's Cardiac Arrhythmia Suppression Trial (CAST), a long-term, muliticentered, randomized, double-blind study in patients with asymptomatic non-life-threatening ventricular arrhythmias who had a myocardial infarction more than six days but less than two years previously, an excessive mortality or non-fatal cardiac arrest rate (7.7%) was seen in patients treated with encainide or flecainide compared with that seen in patients assigned to carefully matched placebo-treated groups (3.0%). The average duration of treatment with encainide or flecainide in this study was 10 months.The applicability of the CAST results to other populations (eg, those without recent myocardial infarction) is uncertain. Considering the known proarrhythmic properties of procainamide and the lack of evidence of improved survival for any antiarrhythmic drug in patients without life-threatening arrhythmias, the use of procainamide hydrochloride as well as other antiarrhythmic agents should be reserved for patients with life-threatening ventricular arrhythmias.Blood DyscrasiasAgranulocytosis, bone marrow depression, neutropenia, hypoplastic anemia and thrombocytopenia in patients receiving procainamide hydrochloride have been reported at a rate of approximately 0.5%. Most of these patients received procainamide hydrochloride within the recommended dosage range. Fatalities have occurred (with approximately 20% to 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 three 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 therapy should be discontinued. Blood counts usually return to normal within one month of discontinuation. Caution should be used in patients with pre-existing marrow failure or cytopenia of any type .
The Pronestyl brand name has been discontinued in the U.S. If generic versions of this product have been approved by the FDA, there may be generic equivalents available.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Antiarrhythmic, Group IA
Uses for Pronestyl
Procainamide injection is used to treat irregular heartbeats and to slow an overactive heart. When the heart has a normal heartbeat (rhythm), it will work more efficiently. Procainamide works by slowing the nerve impulses in the heart and reducing the sensitivity of heart tissues.
This medicine is available only with your doctor's prescription.
The oral dosage forms of this medicine are no longer available in the United States.
Before using Pronestyl
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For this medicine, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to this medicine or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of procainamide injection in the pediatric population. Safety and efficacy have not been established.
No information is available on the relationship of age to the effects of procainamide injection in geriatric patients. However, elderly patients are more likely to have age-related kidney problems, which may require an adjustment in the dose for patients receiving procainamide injection.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking this medicine, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using this medicine with any of the following medicines is not recommended. Your doctor may decide not to treat you with this medication or change some of the other medicines you take.
Using this medicine with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Aripiprazole Lauroxil
- Arsenic Trioxide
- Chloral Hydrate
- Inotuzumab Ozogamicin
- Nalidixic Acid
- Sodium Phosphate
- Sodium Phosphate, Dibasic
- Sodium Phosphate, Monobasic
Using this medicine with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. Discuss with your healthcare professional the use of your medicine with food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of this medicine. Make sure you tell your doctor if you have any other medical problems, especially:
- Heart block or
- Heart rhythm problem (e.g., QT prolongation) or
- Lupus erythematosus, history of—Should not use in patients with these conditions.
- Heart failure, congestive or
- Myasthenia gravis—May make these conditions worse.
- Kidney disease or
- Liver disease—Use with caution. The effects may be increased because of slower removal from the body.
Proper use of Pronestyl
A nurse or other trained health professional will give you this medicine in a hospital. This medicine is given through a needle placed in one of your veins.
Your doctor will only give you a few doses of this medicine until your condition improves, and then you may be switched to an oral medicine that works the same way. If you have any concerns about this, talk to your doctor.
Precautions while using Pronestyl
It is important that your doctor check your progress carefully while you are receiving this medicine to make sure it is working properly. This will allow necessary changes in the amount of medicine you receive and may also help reduce side effects.
Dizziness or lightheadedness may occur with this medicine, especially in elderly patients and when large doses are used. Patients should use extra care to avoid falling. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or not alert.
Pronestyl side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor or nurse immediately if any of the following side effects occur:
- Fever and chills
- joint pain or swelling
- pains with breathing
- skin rash or itching
- Bleeding, blistering, burning, coldness, discoloration of skin, feeling of pressure, hives, infection, inflammation, itching, lumps, numbness, pain, rash, redness, scarring, soreness, stinging, swelling, tenderness, tingling, or warmth at the injection site
- fever or sore mouth, gums, or throat
- hallucinations (seeing, hearing, or feeling things that are not there)
- mental depression
- unusual bleeding or bruising
- unusual tiredness or weakness
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
- Decrease in urination
- dizziness (severe) or fainting
- fast or irregular heartbeat
- nausea and vomiting
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- hardening or thickening of the skin where the needle is placed
- loss of appetite
- Dizziness or lightheadedness
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about Pronestyl (procainamide)
- Side effects
- Drug interactions
- Dosage information
- During pregnancy or Breastfeeding
- Imprints, shape & color data
- Drug class: group I antiarrhythmics
Related treatment guides
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