Procainamide


Concise Prescribing Info
Indications/Uses
Listed in Dosage.
Dosage/Direction for Use
Adult : PO Short-term management of severe or symptomatic arrhythmias; Ventricular arrhythmias 50 mg/kg/day in divided doses 3-6 hrly. IV Short-term management of severe or symptomatic arrhythmias; Ventricular arrhythmias 100 mg every 5 mins until arrhythmia has been suppressed or a max of 1 g has been reached.
Dosage Details
Intravenous
Short-term management of severe or symptomatic arrhythmias, Ventricular arrhythmias
Adult: Dilute in 5% glucose soln and given in doses of 100 mg every 5 min at a rate not exceeding 50 mg/min until arrhythmia has been suppressed or a max of 1 g has been reached. Alternatively admin by continuous infusion of 500-600 mg over 25-30 min with ECG monitoring followed by infusion at a rate of 2-6 mg/min.
Child: Loading dose of 10-12 mg/kg, followed by continuous infusion of 20-75 mcg/kg/min.
Elderly: Dosage reduction or increase in dosing intervals is recommended.

Oral
Short-term management of severe or symptomatic arrhythmias, Ventricular arrhythmias
Adult: 50 mg/kg daily in divided doses every 3-6 hr.
Child: 15-50 mg/kg daily in 4 divided doses.
Elderly: Dosage reduction or increase in dosing intervals is recommended.
Renal Impairment
Dosage reduction or increase in dosing intervals is recommended.
Hepatic Impairment
Dosage reduction is recommended.
Administration
Should be taken on an empty stomach. Best taken on an empty stomach 1 hr before or 2 hr after meals. May also be taken w/ food or milk to avoid stomach upset.
Contraindications
Heart block, SLE, heart failure, hypotension, myasthenia gravis, digoxin toxicity, lactation.
Special Precautions
Myocardial damage or severe organic heart disease, asthma. Perform regular blood tests. Screen for lupus erythematosus. Serum antinuclear factor should be carried out before and regularly during therapy. Pregnancy, elderly, hepatic and renal impairment. May worsen torsade de pointes. Pre-treatment with digoxin may be necessary if procainamide is used in the treatment of atrial tachycardia. IV admin may cause severe hypotension, thus slow inj and monitoring of ECG and BP are recommended.
Adverse Reactions
Severe hypotension, ventricular fibrillation and asystole with rapid IV admin. Drug-induced SLE syndrome; blood disorders; fever myocardial depression, heart failure, agranulocytosis after prolonged treatment, psychosis, angioedema, hepatomegaly; skin irritation; hypergammaglobulinaemia; GI disorders; CNS effects.
IM/IV/Parenteral/PO: C
Drug Interactions
May enhance effects of antihypertensives, other antiarrhythmics, antimuscarinics and neuromuscular-blocking drugs and diminish those of parasympathomimetics. Increased clearance when used with alcohol. Increased plasma concentrations and toxicity of procainamide when used with trimethoprim.
Potentially Fatal: Increased risk of arrhythmias with terfenadine and antipsychotics that prolong QT interval.
Action
Description: Procainamide directly interferes with depolarization of the cell membrane by blocking the fast inward current of Na into cardiac cells. It slows the rate of change of the depolarization phase of the action potential, moderately prolong the PR, QRS and QT intervals on ECG monitoring. It also has local anesthetic properties.
Pharmacokinetics:
Absorption: Readily and almost completely absorbed.
Distribution: Widely distrbuted and only about 15-20% bound to plasma proteins. Crosses the placenta and passes into the breast milk.
Metabolism: Hydrolysis and acetylation in the liver,
Excretion: Excreted in the urine via active renal secretion. About 30-70% as unchanged drug. Elimination half-life of procainamide is about 2.5-5 hr.
MIMS Class
Disclaimer: This information is independently developed by MIMS based on Procainamide from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2020 MIMS. All rights reserved. Powered by MIMS.com
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