Flecainide
Tambocor
A potent sodium channel blocker with marked efficacy on atrial arrhythmias in structurally normal hearts. The CAST trial showed increased mortality after myocardial infarction — that boundary remains the most important fact in the drug's history.
Increased mortality in structural heart disease and after myocardial infarction. Contraindicated in ischaemic heart disease and impaired left ventricular function.
Dosing in adults
| Indication | Regimen | Comment |
|---|---|---|
| Paroxysmal atrial fibrillation, maintenance | 50–100 mg × 2 orally | always combined with an AV-blocking agent |
| "Pill in the pocket" | 200–300 mg orally as a single dose | first use must be evaluated in a monitored setting |
| Pharmacological cardioversion, intravenous | 2 mg/kg over 10 minutes, maximum 150 mg | under continuous ECG monitoring |
| Supraventricular tachycardia | 50 mg × 2 orally, up to 100 mg × 2 | second-line choice |
Reduce dose at eGFR below 35; a substantial proportion is excreted renally.
Reduce dose and monitor plasma concentration in hepatic impairment.
Paediatric cardiologist only; dosed by body surface area.
Never give without concurrent AV-blocking treatment: flecainide can convert atrial fibrillation into slow atrial flutter conducted 1:1 with a ventricular rate above 200.
Pharmacokinetics
- BIOAVAIL.
- 90 %
- Vd
- 5–10 l/kg
- t½
- 12–27 h
- PROTEIN BINDING
- 40 %
- METABOLISM
- CYP2D6
- EXCRETION
- Renal, 30 % unchanged
- INHIBITS
- —
- ONSET
- 1–3 h orally