Flecainide
Indications
Flecainide is used for:
Arrhythmias (Prevention)
Adult Dose
Oral
Arrhythmias (Prevention)
PSVT and paroxysmal atrial fibrillation
50 mg PO BID; may increase by 50 mg every 4 days; do not exceed 300 mg/day
Sustained VT
100 mg PO BID initiated in hospital; may increase by 50 mg every 4 days; do not exceed 400 mg/day
Hepatic impairment
Use only if benefits outweigh risk; monitor plasma levels regularly; reduce dose as necessary
Child Dose
Arrhythmias
<6 months: 50 mg/m²/day PO divided q8-12hr
>6 months: 100 mg/m²/day PO divided q8-12hr
Not to exceed 200 mg/m²/day
Renal Dose
Renal impairment
Severe (<35 mL/min): 100 mg PO qDay or 50 mg PO BID
>25 mL/min: 100 mg PO BID
Administration
May be taken with or without food.
Contra Indications
Pre-existing 2nd- or 3rd-degree AV block w/o pacemaker, right bundle branch block associated w/ left hemiblock w/o pacemaker, cardiogenic shock, heart failure, history of MI, known Brugada syndrome.
Precautions
Patient w/ pacemakers, atrial fibrillation following cardiac surgery, atrial flutter, and structural heart disease. Renal (CrCl ≤35 mL/min) and significant hepatic impairment. Elderly. Childn. Pregnancy and lactation. Patient Counselling This drug may cause dizziness and visual disturbances, if affected, do not drive or operate machinery. Monitoring ParametersMonitor ECG, BP, plasma levels, and resp function.
Pregnancy-Lactation
Pregnancy category: C
Lactation: Enters breast milk
Interactions
Increased incidence of cardiac arrhythmias w/ other antiarrhythmics or arrhythmogenic drugs. Additive negative inotropic effects w/ Class II antiarrhythmics. Increased plasma conc w/ amiodarone, cimetidine quinidine, and ritonavir. Hypokalaemia may result w/ diuretics, corticosteroids, and laxatives.
Adverse Effects
Side effects of Flecainide :
>10%
Visual disturbances (5-16%)
Dizziness (10-19%)
1-10%
Arrhythmias
Edema (1-4%)
Asthenia (2-5%)
Palpitations (2-7%)
Fatigue (3-8%)
Tremors (2-5%)
Constipation (1-4%)
Nausea (5-9%)
Chest pain (1-5%)
Dyspnea (5-10%)
Headache (5-10%)
Abdominal pain (1-3%)
Malaise (1-3%)
Fever (1-3%)
Tachycardia (1-3%)
Sinus pause/arrest (1-3%)
Vomiting (1-3%)
Diarrhea (1-3%)
Dyspepsia (1-3%)
Anorexia (1-3%)
Rash (1-3%)
Diplopia (1-3%)
Hypoesthesia (1-3%)
Paresthesia (1-3%)
Paresis (1-3%)
Ataxia (1-3%)
Flushing (1-3%)
Diaphoresis (1-3%)
Vertigo (1-3%)
Syncope (1-3%)
Somnolence (1-3%)
Tinnitus (1-3%)
Anxiety (1-3%)
Insomnia (1-3%)
Depression (1-3%)
Mechanism of Action
Flecainide, an amide anaesthetic, belongs to Class Ic antiarrhythmic agents. It inhibits the transmembrane influx of extracellular Na ions via fast channels on cardiac tissues resulting to a decrease in rate of depolarisation of the action potential, prolonging the PR and QRS intervals. At high concentrations, it exerts inhibitory effects on slow Ca channels, accompanied by moderate negative inotropic effect.