[Acute and long-term antiarrhythmia effect of encainide in chronic atrial extrasystole].

Abstract

The antiarrhythmic effects of Encainide in acute intravenous and long-term oral therapy were investigated in 10 patients suffering from chronic atrial ectopic beats previously non-responsive to conventional therapy. The efficacy of Encainide was assessed by 24-hour ECG monitoring during the acute i.v. application and in 4 week intervals over a period of 4 to 6 months. Plasma concentrations of Encainide and the O-demethyl- (ODE) and 3-methoxy-O-demethyl metabolites (3-MODE) were determined after i.v. administration and during oral therapy. A significant reduction of arrhythmias by 76% was found after 1.0 mg/kg Encainide given intravenously. Atrial ectopic beats with bundle branch block QRS-morphology were reduced by more than 90% after only 0.5 mg/kg. During long-term oral therapy 6 of the 9 patients were treated successfully. Following i.v. administration Encainide-plasma concentrations rapidly decreased with a half life of approximately 75 min in the final distribution phase. During oral therapy Encainide levels were not detectable under steady state conditions 4 to 6 hours after the last dose, or they were only minimal, but the average concentrations of ODE and 3-MODE were 71.3 +/- 21.3 and 75.6 +/- 13.5 ng/ml. Encainide increased PR interval and QRS duration significantly. QT-interval changed as a result of the QRS-prolongation. Encainide was well tolerated during acute and chronic therapy. No severe side effects were seen, except in one case, in which dose reduction by 50% was necessary because of blurred vision.(ABSTRACT TRUNCATED AT 250 WORDS)

• Authors: J Thale, H Klein, R G Shanks, F Bender
• Journal: Zeitschrift fur Kardiologie (Z Kardiol) Vol. 74 Issue 4 Pg. 220-7 (Apr 1985) ISSN: 0300-5860 [Print] Germany
• Vernacular Title: Antiarrhythmische Akut- und Langzeitwirkung von Encainid bei chronischer Vorhofextrasystolie.
• PMID: 2408392 (Publication Type: English Abstract, Journal Article)

Chemical References

• Anilides
• Anti-Arrhythmia Agents
• Encainide

Topics

• Administration, Oral
• Adult
• Aged
• Anilides (adverse effects, blood, therapeutic use)
• Anti-Arrhythmia Agents (adverse effects, blood, therapeutic use)
• Cardiac Complexes, Premature (drug therapy)
• Dose-Response Relationship, Drug
• Electrocardiography
• Encainide
• Female
• Half-Life
• Heart Atria (drug effects)
• Heart Rate (drug effects)
• Humans
• Infusions, Parenteral
• Long-Term Care
• Male
• Metabolic Clearance Rate
• Middle Aged