Withdrawn from the market (safety)

Encainide

ENKAID

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Encainide ballicule: receptor binding, kinetics and half-life diagram — Mechanism of action: Encainide ballicule

What it isClass IC antiarrhythmic; withdrawn.

Why this oneSuppressed ventricular ectopy effectively, which is exactly why it was trialled.

What limits it⚑ CAST showed it INCREASED mortality after myocardial infarction — the trial that ended surrogate-endpoint prescribing in cardiology.

Encainide molecular structure (skeletal formula) — Molecular structure: Encainide

Encainide prescription history

Animated chart of estimated U.S. prescriptions per year, Antiarrhythmics (class I/III) (1930–2026). Encainide enters in 1987 (estimated).

FDA-approved for

ventricular arrhythmias (withdrawn 1991) (1986)

⚠ BOXED WARNING

Proarrhythmia and excess mortality after myocardial infarction

Classes and tags

Clinical profile

Therapeutic safety burden3 / 4

Direct muscarinic antagonism0 / 4

Embryofetal risk1 / 4

Defining liabilityFatal proarrhythmia in vulnerable cardiac patients

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Self-check

What did CAST find with encainide after MI?
Increased mortality.
Which rhythm finding did encainide suppress?
Ventricular ectopy.