Brands, Medical Use, Clinical Data
- Tablet (extended-release)
Brands / Synonyms
Biocoryl; Novocainamid; Novocainamide; Novocaine Amide; Novocamid; Procainamide; Procainamide Hcl; Procaine Amide; Procamide; Procan; Procan Sr; Procanbid; Procapan; Promine; Pronestyl; Pronestyl-SR; Pronestyl-Sr
For the treatment of life-threatening ventricular arrhythmias.
Procainamide is an agent indicated for production of local or regional anesthesia and in the treatment of ventricular tachycardia occurring during cardiac manipulation, such as surgery or catheterization, or which may occur during acute myocardial infarction, digitalis toxicity, or other cardiac diseases. The mode of action of the antiarrhythmic effect of Procainamide appears to be similar to that of procaine and quinidine. Ventricular excitability is depressed and the stimulation threshold of the ventricle is increased during diastole. The sinoatrial node is, however, unaffected.
Mechanism of Action
Procainamide is sodium channel blocker. It stabilizes the neuronal membrane by inhibiting the ionic fluxes required for the initiation and conduction of impulses thereby effecting local anesthetic action.
75 to 95%
LD50=95 mg/kg (rat, IV); LD50=312 mg/kg (mouse, oral); LD50=103 mg/kg (mouse, IV); LD50=250 mg/kg (rabbit, IV)
Biotrnasformation / Drug Metabolism
Complete heart block
Procainamide should not be administered to patients with complete heart block because of its effects in
suppressing nodal or ventricular pacemakers and the hazard of asystole. It may be difficult to recognize complete
heart block in patients with ventricular tachycardia; but if significant slowing of ventricular rate occurs during
procainamide treatment without evidence of A-V conduction appearing procainamide should be stopped. In cases of
second degree A-V block or various types of hemiblock, procainamide should be avoided or discontinued because of the
possibility of increased severity of block, unless the ventricular rate is controlled by an electrical pacemaker.
In patients sensitive to procaine or other ester-type local anesthetics, cross sensitivity, to procainamide is
unlikely. However, it should be borne in mind, and procainamide should not be used if it produces acute allergic
dermatitis, asthma or anaphylactic symptoms.
An established diagnosis of systemic lupus erythematosus is a contraindication to procainamide therapy, since
aggravation of symptoms is highly likely.
Torsades de Pointes
In the unusual ventricular arrhythmia called "les torsades de pointes" (twistings of the points) characterized by
alternation of one or more ventricular premature beats in the directions of the QRS complexes on ECG in persons with
prolonged Q-T and often enhanced U waves, Group 1A antiarrhythmic drugs are contraindicated. Administration of
procainamide in such cases may aggravate this special type of ventricular extrasystole or tachycardia instead of
If other antiarrhythmic drugs are being used additive effects on the heart may occur with procainamide
administration, and dosage reduction may be necessary.
Anticholinergic drugs administered concurrently with procainamide may produce additive antivagal effects on A-V
nodal conduction, although this is not as well documented for procainamide as for quinidine.
Patients taking procainamide who require neuromuscular blocking agents such as succinylcholine may require less
than usual doses of the latter, due to procainamide effects on reducing acetylcholine release.