Энкаинид

Description

Encainide is a class IC antiarrhythmic drug according to the Vaughan Williams classification, a blocker of sodium channels of cardiomyocytes. Suppresses the influx of sodium ions during the depolarization phase of the action potential, stabilizes the cell membrane and slows down the conduction of impulses through the conduction system of the heart, which is used to suppress ventricular ectopic activity. Developed under the laboratory designation MJ 9067. Infamous for the CAST (Cardiac Arrhythmia Suppression Trial) study: post-myocardial infarction patients treated with encainide or flecainide to suppress asymptomatic ventricular arrhythmia had higher mortality from arrhythmia and cardiogenic shock compared with placebo, which is why the arms of the study with these drugs were terminated early in 1989. This study marked a turning point in cardiology, showing that suppression of an electrocardiographic marker (ectopia) does not equal a reduction in the risk of death.

Basic Attributes

• CAS No: 66778-36-7 (sister number 37612-13-8)
• Chemical formula: C22H28N2O2
• Molecular weight: 352.47
• Exact weight: 352.47
• DSSTox ID: DTXSID0022983
• ATC code (ATC): C - drugs for the treatment of the cardiovascular system
• PSA specifications: 41.6
• XLogP3: 4

Physico-chemical characteristics

• Appearance: Solid
• Melting point: 128–131 °C (in acetonitrile)
• Solubility in water: 4.01×10⁻³ g/l

Synonyms

MJ 9067; systematic name 4-Methoxy-N-[2-[2-(1-methyl-2-piperidinyl)ethyl]phenyl]benzamide (Benzamide,4-methoxy-N-[2-[2-(1-methyl-2-piperidinyl)ethyl]phenyl]-).

Scope of application

Used in clinical practice as an antiarrhythmic agent to suppress ventricular arrhythmias. After the publication of the results of the CAST study, the use of the drug was sharply reduced due to a proven increase in mortality in post-infarction patients, and currently encainide remains important primarily as a pharmacological reference standard and the subject of study in clinical pharmacology courses as an example of the IC class of antiarrhythmics with proarrhythmogenic potential.

Storage and transportation

Store in an airtight container at room temperature, protected from light and moisture, out of reach of unauthorized persons due to the pharmacological activity of the substance. No special high-risk transport codes have been assigned; When sending analytical and pharmacopoeial standards, the requirements for the transportation of medicinal substances are observed.

More information about CAST lessons

The results of the CAST study have revolutionized cardiologists' understanding of the relationship between suppression of ventricular ectopy and clinical outcome: before the publication of the results, it was taken for granted that reducing the number of extrasystoles on the ECG reduces the risk of sudden cardiac death. Encainide and flecainide effectively eliminated ectopic activity, but at the same time had proarrhythmogenic potential against the background of structurally damaged myocardium after myocardial infarction, which explains the excess mortality in the active treatment groups. This lesson has formed the basis for modern requirements for evidence of outcomes (rather than surrogate ECG markers) when registering new antiarrhythmic drugs.