Related Experiment Videos
Plasma flecainide concentrations following acute myocardial infarction
Abstract:
Plasma flecainide concentrations were measured in 10 patients with acute myocardial infarction. Following an oral loading dose of 300 mg plasma concentrations were highly variable and unpredictable. Subsequently, doses of 150 mg twice daily produced mean plasma flecainide concentrations consistently above 400 micrograms/1 within 48 hours. Oral flecainide is, therefore, subject to the same problems of varying oral bioavailability as other antiarrhythmic drugs tested following acute myocardial infarction and, initially, an intravenous regime remains preferable. Mild pulmonary oedema occurred in six patients and, although it responded to one dose of frusemide and did not recur, flecainide must be used with caution when significant left ventricular dysfunction is suspected.
Insights
Oral flecainide shows variable bioavailability in acute myocardial infarction patients, necessitating caution. Initial intravenous administration is preferred due to unpredictable oral absorption and potential adverse effects like pulmonary edema.
Area of Science:
- Cardiology
- Pharmacology
- Internal Medicine
Background:
- Acute myocardial infarction (AMI) presents challenges for antiarrhythmic drug therapy.
- Flecainide is a Class Ic antiarrhythmic agent.
- Understanding drug bioavailability is crucial for effective treatment post-AMI.
Purpose of the Study:
- To evaluate plasma flecainide concentrations in patients with acute myocardial infarction.
- To assess the variability and predictability of oral flecainide dosing.
- To determine the safety and efficacy of flecainide in this patient population.
Main Methods:
- 10 patients with acute myocardial infarction were enrolled.
- Oral loading dose of 300 mg flecainide was administered.
- Subsequent maintenance doses of 150 mg twice daily were given.
- Plasma flecainide concentrations were monitored.
Main Results:
- Oral loading doses resulted in highly variable and unpredictable plasma flecainide concentrations.
- Maintenance doses of 150 mg twice daily achieved mean concentrations above 400 µg/L within 48 hours.
- Six patients experienced mild pulmonary edema, which resolved with frusemide treatment.
Conclusions:
- Oral flecainide exhibits variable bioavailability in AMI patients, similar to other antiarrhythmics.
- Intravenous administration of flecainide is initially preferable due to absorption variability.
- Flecainide should be used cautiously in patients with suspected left ventricular dysfunction due to the risk of pulmonary edema.