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.

Side 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%)

Mode 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.