Procainamide
Encyclopedia
Procainamide INN
(icon; trade names Pronestyl, Procan, Procanbid) is a pharmaceutical antiarrhythmic agent
used for the medical
treatment
of cardiac arrhythmias, classified by the Vaughan Williams classification system as class Ia.
(Na+) channels and prolongs the cardiac
action potential
(outward potassium
(K+) currents may be blocked).
This results in slowed conduction, and ultimately the decreased rate of rise of the action potential, which may result in widening of QRS
on electrocardiogram
(ECG).
is used for both supraventricular and ventricular arrhythmias.
For example, it can be used to convert new-onset atrial fibrillation
, though it is suboptimal for this purpose. It can also be used to treat Wolf-Parkinson-White syndrome by prolonging the refractory period of the accessory pathway. Typically use is secondary to lidocaine in patients who are allergic to lidocaine or dysrhythmias that are refractory to lidocaine.
When administered intravenously, a loading dose
should first be given, though care should be taken not to cause hypotension
.
Procainamide's major active metabolite is N-acetyl procainamide
(NAPA), which is approximately equipotent with the parent drug as an antiarrhythmic agent. NAPA has an elimination half-life about twice that of procainamide, and it can reach somewhat higher plasma levels during chronic procainamide administration.
Loading dose is 100 mg IV bolus given slowly over 5 minutes. Max dose is 17 mg/kg. Use is discontinued when dysrhythmia is suppressed, or if hypotension ensues, QRS complex widens by 50% or more, or maximum dose is achieved.
, myalgia
, hypersensitivity reaction
s (fever
, agranulocytosis
), Drug-Induced Lupus Erythematosus
(particularly in slow-acetylators), and proarrhythmic effects (e.g., torsades de pointes
). Treatment with procainamide can cause antibody production against cellular components, accounting for the systemic lupus erythematosus-like adverse reactions.
International Nonproprietary Name
An International Nonproprietary Name is the official nonproprietary or generic name given to a pharmaceutical substance, as designated by the World Health Organization...
(icon; trade names Pronestyl, Procan, Procanbid) is a pharmaceutical antiarrhythmic agent
Antiarrhythmic agent
Antiarrhythmic agents are a group of pharmaceuticals that are used to suppress abnormal rhythms of the heart , such as atrial fibrillation, atrial flutter, ventricular tachycardia, and ventricular fibrillation....
used for the medical
Medicine
Medicine is the science and art of healing. It encompasses a variety of health care practices evolved to maintain and restore health by the prevention and treatment of illness....
treatment
Pharmacotherapy
Pharmacotherapy is the treatment of disease through the administration of drugs. As such, it is considered part of the larger category of therapy....
of cardiac arrhythmias, classified by the Vaughan Williams classification system as class Ia.
History
Procainamide was approved by the US FDA on June 2, 1950, under the brand-name Pronestyl. It was launched by Squibb in 1951.Mechanism
It blocks open sodiumSodium
Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
(Na+) channels and prolongs the cardiac
Heart
The heart is a myogenic muscular organ found in all animals with a circulatory system , that is responsible for pumping blood throughout the blood vessels by repeated, rhythmic contractions...
action potential
Action potential
In physiology, an action potential is a short-lasting event in which the electrical membrane potential of a cell rapidly rises and falls, following a consistent trajectory. Action potentials occur in several types of animal cells, called excitable cells, which include neurons, muscle cells, and...
(outward potassium
Potassium
Potassium is the chemical element with the symbol K and atomic number 19. Elemental potassium is a soft silvery-white alkali metal that oxidizes rapidly in air and is very reactive with water, generating sufficient heat to ignite the hydrogen emitted in the reaction.Potassium and sodium are...
(K+) currents may be blocked).
This results in slowed conduction, and ultimately the decreased rate of rise of the action potential, which may result in widening of QRS
QRS complex
The QRS complex is a name for the combination of three of the graphical deflections seen on a typical electrocardiogram . It is usually the central and most visually obvious part of the tracing. It corresponds to the depolarization of the right and left ventricles of the human heart...
on electrocardiogram
Electrocardiogram
Electrocardiography is a transthoracic interpretation of the electrical activity of the heart over a period of time, as detected by electrodes attached to the outer surface of the skin and recorded by a device external to the body...
(ECG).
Uses
This drugMedication
A pharmaceutical drug, also referred to as medicine, medication or medicament, can be loosely defined as any chemical substance intended for use in the medical diagnosis, cure, treatment, or prevention of disease.- Classification :...
is used for both supraventricular and ventricular arrhythmias.
For example, it can be used to convert new-onset atrial fibrillation
Atrial fibrillation
Atrial fibrillation is the most common cardiac arrhythmia . It is a common cause of irregular heart beat, identified clinically by taking a pulse. Chaotic electrical activity in the two upper chambers of the heart result in the muscle fibrillating , instead of achieving coordinated contraction...
, though it is suboptimal for this purpose. It can also be used to treat Wolf-Parkinson-White syndrome by prolonging the refractory period of the accessory pathway. Typically use is secondary to lidocaine in patients who are allergic to lidocaine or dysrhythmias that are refractory to lidocaine.
Administration
Procainamide is administered intravenously or orally.When administered intravenously, a loading dose
Loading dose
A loading dose is an initial higher dose of a drug that may be given at the beginning of a course of treatment before dropping down to a lower maintenance dose.A loading dose is most useful for drugs that are eliminated from the body relatively slowly...
should first be given, though care should be taken not to cause hypotension
Hypotension
In physiology and medicine, hypotension is abnormally low blood pressure, especially in the arteries of the systemic circulation. It is best understood as a physiologic state, rather than a disease. It is often associated with shock, though not necessarily indicative of it. Hypotension is the...
.
Procainamide's major active metabolite is N-acetyl procainamide
N-Acetyl procainamide
N-Acetylprocainamide is the N-acetylated metabolite of procainamide. It is a Class III antiarrhythmic agent, whereas procainamide is a Class Ia antiarrhythmic drug...
(NAPA), which is approximately equipotent with the parent drug as an antiarrhythmic agent. NAPA has an elimination half-life about twice that of procainamide, and it can reach somewhat higher plasma levels during chronic procainamide administration.
Loading dose is 100 mg IV bolus given slowly over 5 minutes. Max dose is 17 mg/kg. Use is discontinued when dysrhythmia is suppressed, or if hypotension ensues, QRS complex widens by 50% or more, or maximum dose is achieved.
Side effects
Adverse effects include rashRash
A rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracked or blistered, swell and may be painful. The causes, and...
, myalgia
Myalgia
Myalgia means "muscle pain" and is a symptom of many diseases and disorders. The most common causes are the overuse or over-stretching of a muscle or group of muscles. Myalgia without a traumatic history is often due to viral infections...
, hypersensitivity reaction
Hypersensitivity
Hypersensitivity refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity. These reactions may be damaging, uncomfortable, or occasionally fatal. Hypersensitivity reactions require a pre-sensitized state of the host. The four-group classification...
s (fever
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...
, agranulocytosis
Agranulocytosis
Granulopenia, also known as Agranulosis or Agranulocytosis, is an acute condition involving a severe and dangerous leukopenia , most commonly of neutrophils causing a neutropenia in the circulating blood. It represents a severe lack of one major class of infection-fighting white blood cells...
), Drug-Induced Lupus Erythematosus
Drug-induced lupus erythematosus
Drug-induced lupus erythematosus is an autoimmune disorder caused by chronic use of certain drugs. These drugs cause an autoimmune response producing symptoms similar to those of SLE...
(particularly in slow-acetylators), and proarrhythmic effects (e.g., torsades de pointes
Torsades de pointes
Torsades de pointes, or simply torsades, is a French term that literally means "twisting of the points". It was first described by Dessertenne in 1966 and refers to a specific, rare variety of ventricular tachycardia that exhibits distinct characteristics on the electrocardiogram .- Presentation...
). Treatment with procainamide can cause antibody production against cellular components, accounting for the systemic lupus erythematosus-like adverse reactions.