Procainamide

Teratogenic Effects

Animal reproduction studies have not been conducted with procainamide. It also is not known whether procainamide can cause fetal harm when administered to a pregnant woman or can affect reproduction capacity. Procainamide should be given to a pregnant woman only if clearly needed.

Both procainamide and N-acetylprocainamide are excreted in human milk, absorbed by the nursing infant. Because of the potential for serious adverse reactions in nursing infants, a decision to discontinue nursing or the drug should be made, taking into account the importance of the drug to the mother.

Long-term studies in animals have not been performed.

Cardiovascular System: Hypotension and serious disturbances of cardiorhythm such as ventricular asystole or fibrillation are more common with intravenous administration of PA than with intramuscular administration. Because PA is a peripheral vasodilator in concentrations higher than the usual therapeutic range, transient high plasma levels which may occur especially during intravenous administration may produce temporary but at times severe lowering of blood pressure.

Multisystem: A lupus erythematosus-like syndrome of arthralgia, pleural or abdominal pain, and sometimes 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. 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.

Hematologic: Neutropenia, thrombocytopenia, or hemolytic anemia may rarely be encountered. Agranulocytosis has occurred after repeated use of PA, and deaths have been reported.

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

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

Nervous System: Dizziness or giddiness, weakness, mental depression and psychosis with hallucinations have been reported.

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.