FLEK-a-nide

Therapeutic Classification: antiarrhythmics (class IC)

• Life-threatening ventricular arrhythmias, including ventricular tachycardia.
• Supraventricular tachyarrhythmias including:
  • Paroxysmal supraventricular tachycardia,
  • Paroxysmal atrial fibrillation/flutter.

Unlabeled Uses:

• Single dose treatment of atrial fibrillation.

• Slows conduction in cardiac tissue by altering transport of ions across cell membranes.

• Suppression of arrhythmias.

Absorption: Well absorbed from the GI tract following oral administration.

Distribution: Widely distributed to tissues.

Metabolism/Excretion: Mostly metabolized by liver; 30% excreted unchanged by kidneys.

Half-life: 11–14 hr.

(antiarrhythmic effects)

Contraindicated in:

• Hypersensitivity
• Cardiogenic shock.

Use Cautiously in:

• HF (dose ↓ may be required)
• Pre-existing sinus node dysfunction or 2nd- or 3rd-degree heart block (without a pacemaker)
• Renal impairment (↓ dose)
• OB: Use during pregnancy only if potential maternal benefit justifies potential fetal risk.

CV: ARRHYTHMIAS, HF, chest pain.

EENT: blurred vision, visual disturbances.

GI: anorexia, constipation, drug-induced hepatitis, nausea, stomach pain, vomiting.

Derm: rash.

Neuro: dizziness, anxiety, depression, fatigue, headache, tremor.

Drug-Drug:

• ↑risk of arrhythmias with other antiarrhythmics, including calcium channel blockers.
• Disopyramide, beta blockers, or verapamil may have ↑ myocardial depressant effects; combination use should be undertaken cautiously.
• Amiodarone doubles flecainide levels (↓ flecainide dose by 50%).
• May ↑ digoxin levels.
• Concurrent beta blocker therapy may cause ↑ levels of beta blocker and flecainide.
• Alkalinizing agents promote reabsorption, ↑ levels, and may cause toxicity.
• Acidifying agents↑ renal elimination and may ↓ effectiveness of flecainide (if urine pH <5).

Drug-Food:

• Foods that ↑ urine pH to >7 result in ↑ levels (strict vegetarian diet).
• Foods or beverages that ↓ urine pH to <5 ↑ renal elimination and may ↓ effectiveness of flecainide (acidic juices).

Ventricular Tachycardia

• PO (Adults): 100 mg every 12 hr initially, ↑ by 50 mg twice daily until response is obtained or maximum total daily dose of 400 mg is reached. Some patients may require every 8 hr dosing.

Paroxysmal Supraventricular Tachycardia/Paroxysmal Atrial Fibrillation/Flutter

• PO (Adults): 50 mg every 12 hr initially, ↑ by 50 mg twice daily until response is obtained or maximum total daily dose of 300 mg is reached. Some patients may require every 8 hr dosing.

Atrial Fibrillation Conversion (unlabeled)

• PO (Adults): 200-mg or 300-mg single dose.

(Generic available)

• Tablets: 50 mg; 100 mg; 150 mg;

• Monitor ECG or Holter monitor prior to and periodically during therapy. May cause QRS widening, PR prolongation, and QT prolongation.
• Monitor BP and pulse periodically during therapy.
• Monitor intake and output ratios and daily weight. Assess patient for signs of HF (peripheral edema, rales/crackles, dyspnea, weight gain, jugular venous distention).

• Evaluate renal, pulmonary, and hepatic function and CBC periodically on patients receiving long-term therapy. Discontinue flecainide if bone marrow depression occurs.
  • May cause ↑ in serum alkaline phosphatase during prolonged therapy.

• Therapeutic blood levels range from 0.2 to 1.0 mcg/mL. Monitor plasma trough levels frequently during dose adjustment in patients with severe renal or hepatic impairment or in patients with HF and moderate renal impairment.

• Previous antiarrhythmic therapy (except lidocaine) should be withdrawn 2–4 half-lives before starting flecainide.
  • Start therapy in a hospital setting to monitor for increase in arrhythmias.
  • Make dose adjustments at least 4 days apart because of the long half-life of flecainide.
• PO: May be administered with meals if GI irritation becomes a problem.

• Instruct patient to take medication around the clock as directed at evenly spaced intervals, even if feeling better. Take missed doses as soon as remembered if within 6 hr; omit if remembered later. Gradual dose reduction may be necessary.
• May cause dizziness or visual disturbances. Caution patient to avoid driving and other activities requiring alertness until response to medication is known.
• Advise patient to notify health care professional of medication regimen prior to treatment or surgery.
• Instruct patient to notify health care professional if chest pain, shortness of breath, or diaphoresis occurs.
• Advise females of reproductive potential to notify health care professional if pregnancy is planned or suspected or if breastfeeding.
• Advise patient to carry identification describing disease process and medication regimen at all times.
• Emphasize the importance of follow-up exams to monitor progress.

• Decrease in frequency of life-threatening ventricular arrhythmias.
• Decrease in supraventricular tachyarrhythmias.

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