Procainamide Side Effects

It is possible that some side effects of procainamide may not have been reported. These can be reported to the FDA here. Always consult a healthcare professional for medical advice.

For the Consumer

Applies to procainamide: intravenous solution

As well as its needed effects, procainamide may cause unwanted side effects that require medical attention.

If any of the following side effects occur while taking procainamide, check with your doctor or nurse immediately:

Less common
  • 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
  • Confusion
  • 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

If any of the following symptoms of overdose occur while taking procainamide, get emergency help immediately:

Symptoms of overdose
  • Decrease in urination
  • dizziness (severe) or fainting
  • drowsiness
  • fast or irregular heartbeat
  • nausea and vomiting

Some procainamide side effects may not need any medical attention. As your body gets used to the medicine these side effects may disappear. Your health care professional may be able to help you prevent or reduce these side effects, but do check with them if any of the following side effects continue, or if you are concerned about them:

More common
  • Diarrhea
  • hardening or thickening of the skin where the needle is placed
  • loss of appetite
Less common
  • Dizziness or lightheadedness

For Healthcare Professionals

Applies to procainamide: compounding powder, injectable solution, oral capsule, oral tablet, oral tablet extended release


Some side effects of procainamide are related to serum levels of the parent compound and its metabolite, N-acetylprocainamide (NAPA). Side effects are uncommon at levels less than 4 mg per liter, more common at 7 to 8 mg per liter, and expected at 16 mg per liter. Side effects may be more likely and more severe in patients with renal insufficiency.


Cardiovascular side effects may be acute and serious, such as hypotension, polymorphous ventricular tachycardia, or asystole. Administration of intravenous procainamide in dosages that do not exceed 20 mg/min minimizes the risk of hypotension, and should be considered in patients with low blood pressure and/or cardiac dysfunction. Procainamide may induce QT interval lengthening and torsades de pointes, although less commonly than with quinidine. The possible negative inotropic side effects of procainamide, especially with high serum levels, may be deleterious to some patients with compromised cardiac function.

Procainamide may induce the formation of a circulating immunoglobulin directed against some coagulation factors, which has been associated with deep venous thrombosis. This may induce an elevation in the partial thromboplastin time.

A case of myocarditis without pericarditis and several cases of pericarditis associated with procainamide is reported in association with a lupus-like syndrome.


Many of the cases of procainamide-induced agranulocytosis presented with complaints of sore throat, malaise, or fever. Prompt evaluation of the complete blood count and differential cell count is recommended since rare cases of serious infection, and even death, associated with this problem have been reported.

A case of pure red cell aplasia associated with procainamide, and confirmed by rechallenge, has been reported.

Hematologic side effects are rare, but may be severe. The overall incidence of blood dyscrasias (1980 to 1992) was 0.0022% (90% of affected patients were receiving Procan SR). "Blood dyscrasia" was defined as any diagnosis of agranulocytosis, granulocytopenia, neutropenia, leukopenia, thrombocytopenia, pancytopenia, bone marrow suppression, or aplastic anemia--regardless of severity. These reversible dyscrasias do not appear to be related to drug levels. Periodic monitoring of the complete blood count and careful attention to even minor signs of infection during procainamide therapy is recommended. In addition, lupus anticoagulants, which are evident in 25% to 35% of patients with systemic lupus erythematosus, have been reported in patients treated with procainamide in the absence of other lupus-like symptoms. The presence of such immunoglobulins can lead to thromboembolic complications.


Hypersensitivity reactions include reports of angioedema, urticarial rash, and pruritus. Such reactions may be more likely in patients with a sulfite sensitivity. Though not proven, procainamide-induced hepatitis is believed to be hypersensitivity-mediated.


Immunologic side effects include a lupus-like syndrome. Chronic use of procainamide may induce production of an antinuclear antibody (ANA) in up to 70% of asymptomatic patients after 6 weeks of therapy. This antibody may be associated with a reversible lupus-like syndrome (myalgias, arthralgias, arthritis, and pulmonary or pericardial serositis) in rare cases. Symptoms appear in only approximately 30% of affected patients. Checking the ANA titer every other month or quarterly is recommended, although many clinicians opt to continue the drug in some patients with a positive ANA titer, taking into account the need for procainamide therapy.

The lupus-like syndrome may manifest as arthralgias (most common), fever, chills, myalgias, pericarditis, pleuritis, pleural effusion, hepatomegaly, and hemorrhagic cardiac tamponade. Nephritis and cerebritis are not reported. If periodic monitoring reveals a high antinuclear antibody (ANA) titer, or if the patient develops lupus-like symptoms, reevaluation of the use of procainamide and consideration of aspirin and/or corticosteroid therapy is recommended.

The lupus-like syndrome associated with procainamide shows no predilection for females, is reversible upon discontinuation of procainamide, and is more common among slow acetylators.


Gastrointestinal side effects are usually minor, and include nausea, vomiting, anorexia, and diarrhea.

Nervous system

Nervous system side effects are uncommon, and include case reports of dizziness and tremors.

Rare cases of reversible peripheral neuropathy have been associated with a procainamide-induced lupus-like syndrome.


Musculoskeletal weakness is unusual, but may be more likely in patients with underlying myasthenia gravis (MG). At least one case of respiratory failure due to necrotizing myopathy with diaphragmatic involvement in an elderly patient without evidence of MG has been reported.

A 74-year-old man with post-coronary artery bypass grafting supraventricular arrhythmias developed upper body symmetrical muscle weakness and tenderness two weeks after beginning procainamide. Associated findings included a sterile, exudative pleural effusion, elevated creatinine kinase levels, and positive anti-double stranded DNA and anti-histone antibodies. Renal function and antinuclear antibodies were normal. Procainamide was withdrawn. The patient's weakness progressed over the next seven days. He developed diaphragmatic weakness, respiratory acidosis, and the need for mechanical ventilation. An extensive neuromuscular work-up revealed a necrotizing myopathy and no evidence of impaired neuromuscular junction transmission. The muscle biopsy showed no inflammatory infiltrates and antinuclear antibodies were not present. The patient recovered over the next month.


A case of reversible mania has been reported in a patient with nontoxic serum procainamide levels.

A 45-year-old female undergoing a mitral valve replacement and tricuspid valve repair began experiencing visual hallucinations and other symptoms suggestive of psychosis four days after beginning procainamide. Within 24 hours of discontinuing procainamide, the patient returned to normal sensorium.

Psychiatric side effects include euphoria, hallucinations, psychosis, and mental depression.


Only approximately five cases of procainamide-induced granulomatous hepatitis or intrahepatic cholestasis have been reported. Of the five reported cases, all experienced fever, two had vomiting, one pruritus, and none had lymphadenopathy. The onset of signs and symptoms of liver dysfunction began 1 to 17 days after drug administration, and normalized as soon as one day to as long as several months after drug withdrawal. While the mechanism of injury is not known, most believe procainamide-induced hepatitis to be hypersensitivity-mediated.

Hepatic side effects are rare. Rare cases of reversible cholestatic jaundice associated with procainamide have been reported. These cases were thought to be due to hypersensitivity reactions. Frequent monitoring of liver function tests is recommended in patients with hepatic insufficiency.

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