flecainide acetate

(redirected from Tambocor XL)

flecainide acetate

Apo-Flecainide (CA), Tambocor, Tambocor XL (UK)

Pharmacologic class: Cardiac benzamide local anesthetic

Therapeutic class: Antiarrhythmic (class IC)

Pregnancy risk category C


Inhibits fast sodium channels of myocardial cell membrane. Also slows conduction, shortens action potential, stops paroxysmal reentrant supraventricular tachycardia, and decreases conduction in accessory pathways in Wolff-Parkinson-White syndrome.


Tablets: 50 mg, 100 mg, 150 mg

Indications and dosages

Supraventricular tachyarrhythmias (including paroxysmal supraventricular tachycardia and paroxysmal atrial fibrillation or flutter)

Adults: Initially, 50 mg P.O. q 12 hours, increased by 50 mg b.i.d. q 4 days until desired response occurs or maximum daily dosage of 300 mg is reached

Sustained, life-threatening ventricular tachycardia

Adults: Initially, 100 mg P.O. q 12 hours, increased by 50 mg b.i.d. q 4 days until desired response occurs or maximum daily dosage of 400 mg is reached

Dosage adjustment

• Heart failure

• Renal impairment

Off-label uses

• Ventricular arrhythmias

• Wolff-Parkinson-White syndrome


• Hypersensitivity to drug

• Preexisting atrioventricular block or right bundle-branch block

• Recent MI

• Cardiogenic shock


Use cautiously in:

• heart failure, renal impairment

• patients taking concurrent amiodarone, beta-adrenergic blockers, disopyramide, or verapamil

• pregnant or breastfeeding patients

• children (safety not established).


• Initiate therapy only in hospital setting with trained personnel and continuous ECG monitoring.

• Before giving, correct hypokalemia or hyperkalemia.

• Be aware that dosage may be reduced once arrhythmias have been adequately controlled.

Adverse reactions

CNS: dizziness, anxiety, fatigue, headache, depression, malaise, tremor, weakness, hypoesthesia, paresthesia

CV: chest pain, palpitations, second- or third-degree heart block, heart failure, new or worsening arrhythmias

EENT: blurred vision, visual disturbances, corneal deposits

GI: nausea, vomiting, constipation, abdominal pain, dyspepsia, anorexia

Hepatic: hepatitis

Respiratory: dyspnea

Skin: rash, diaphoresis

Other: edema, fever


Drug-drug. Acidifying drugs: increased renal elimination, decreased efficacy of flecainide (with urine pH below 5)

Alkalizing drugs: increased flecainide blood level, possible toxicity

Amiodarone: doubling of flecainide blood level

Beta-adrenergic blockers: increased blood levels of both drugs

Beta-adrenergic blockers, disopyramide, verapamil: additive myocardial depressant effect

Digoxin: 15% to 25% increase in digoxin blood level

Other antiarrhythmics (including calcium channel blockers): increased risk of arrhythmias

Drug-diagnostic tests. Alkaline phosphatase: increased level (with prolonged therapy)

Drug-food. Foods that decrease urine pH below 5 (such as acidic juices): increased renal elimination and possibly decreased efficacy of drug

Foods that increase urine рH above 7 (as in strict vegetarian diets): increased drug blood level

Drug-behaviors. Smoking: increased plasma clearance and decreased efficacy of drug

Patient monitoring

Monitor ECG for worsening arrhythmias.

• Measure pacing threshold 1 week before therapy starts and again after 1 week of therapy.

• Monitor potassium and flecainide blood levels.

• Assess respiratory status regularly.

• Monitor hepatic function tests.

Patient teaching

Instruct patient to immediately report cardiac or respiratory symptoms, unusual tiredness, or yellowing of skin or eyes.

• Tell patient drug may cause numbness. Advise him to avoid injury to areas with sensory impairment.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration, alertness, and vision.

• Advise patient to minimize GI upset by eating small, frequent servings of food and drinking adequate fluids.

• Tell female patient to inform prescriber if she is pregnant or breastfeeding.

• Inform patient that he'll undergo regular blood testing during therapy.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, and behaviors mentioned above.

flecainide acetate

an oral antiarrhythmic drug.
indications It is prescribed for the treatment of ventricular arrhythmias (e.g., sustained ventricular tachycardia) and for treating supraventricular tachycardia in the absence of conduction defects when other drugs have failed.
contraindications Preexisting second- or third-degree atrioventricular block, right bundle-branch block associated with a left hemiblock in the absence of a pacemaker, cardiogenic shock, and coronary artery disease prohibit its use. Concurrent therapy with disopyramide and verapamil is not recommended, and there is insufficient experience with concurrent use with nifedipine or diltiazem to recommend concurrent use. Should not be administered with other drugs that are highly dependent on CYP3A or CYP2D6 for metabolism such as ritonavir and amprenavir.
adverse effects Among adverse effects reported are new or increased arrhythmias or congestive heart failure, dizziness, visual disturbances, dyspnea, headache, nausea, fatigue, tremor, constipation, and edema.

flecainide acetate

A drug used to treat severe heart irregularities. A brand name is Tambocor.