Betapace

— THERAPEUTIC CATEGORIES —
  • CHF and arrhythmias

Betapace Generic Name & Formulations

General Description

Sotalol HCl 80mg, 120mg, 160mg; scored tabs.

Pharmacological Class

Class II and III antiarrhythmic.

See Also

How Supplied

Tabs—100; AF tabs—60

Mechanism of Action

Sotalol has both beta-adrenoreceptor blocking (Vaughan Williams Class II) and cardiac action potential duration prolongation (Vaughan Williams Class III) antiarrhythmic properties. It prolongs the plateau phase of the cardiac action potential in the isolated myocyte, as well as in isolated tissue preparations of ventricular or atrial muscle (Class III activity). The Class II electrophysiological effects of sotalol are manifested by increased sinus cycle length, decreased AV nodal conduction and increased AV nodal refractoriness. The Class III electrophysiological effects include prolongation of the atrial and ventricular monophasic action potentials, and effective refractory period prolongation of atrial muscle, ventricular muscle, and atrioventricular accessory pathways (where present) in both the anterograde and retrograde directions.

Betapace Indications

Indications

Documented life-threatening ventricular arrhythmias. Maintenance of normal sinus rhythm in patients with highly symptomatic atrial fibrillation/atrial flutter (AFIB/AFL) who are currently in sinus rhythm.

Limitations of Use

Not been shown to enhance survival in patients with life-threatening ventricular arrhythmias. Reserve its use for those in whom AFIB/AFL is highly symptomatic. Patients with paroxysmal AFIB that is easily reversed (eg, by Valsalva maneuver) should usually not be given Betapace/Betapace AF.

Betapace Dosage and Administration

Adult

Initiate and titrate up in a hospital setting that can provide continuous ECG, creatinine clearance monitoring, and cardiac resuscitation. Initially 80mg twice daily. Increase at 3-day intervals in increments of 80mg/day provided the QTc <500msec. Ventricular arrhythmias (usual maintenance): 160–320mg/day divided in 2 or 3 doses (refractory patients may need 480–640mg/day). AFIB/AFL (usual maintenance): 120mg twice daily. Both: renal impairment (CrCl <60mL/min): prolong dosing interval (see full labeling).

Children

<2yrs: see full labeling. ≥2yrs: initially 1.2mg/kg three times daily (3.6mg/kg/day). Titrate up to max 2.4mg/kg three times daily. Adjust dose based on clinical response, heart rate, and QTc.

Betapace Contraindications

Contraindications

Sinus bradycardia. Sick sinus syndrome. 2nd or 3rd degree AV block, unless paced. Long QT syndromes. Cardiogenic shock. Decompensated heart failure. Serum potassium (<4mEq/L). Bronchial asthma or related bronchospastic conditions. Also for AFIB/AFL: baseline QT interval >450msec.

Betapace Boxed Warnings

Boxed Warning

Life-threatening proarrhythmia.

Betapace Warnings/Precautions

Warnings/Precautions

Increased arrhythmia risk in females, renal impairment, reduced heart rate, history of sustained ventricular tachycardia or heart failure, or with higher doses of sotalol. Correct electrolyte imbalances (esp. hypokalemia, hypomagnesemia) and withdraw other antiarrhythmics prior to initiation. If QTc interval ≥500msec; reduce dose, lengthen the dosing interval, or discontinue therapy. Monitor hemodynamics in those with marginal cardiac compensation. Discontinue if symptoms of heart failure occurs. Bronchospastic disease. Increased risk for hypoglycemia esp. in diabetics, children, or those who are fasting (eg, surgery, not eating regularly, or vomiting); monitor. Acid-base imbalance. Hyperthyroidism. History of anaphylaxis. Surgery. Avoid abrupt cessation (withdraw over 1–2 weeks if possible, monitor for angina and acute coronary ischemia). Neonates. Labor & delivery: monitor. Pregnancy. Nursing mothers: not recommended.

Betapace Pharmacokinetics

Absorption

Oral bioavailability: 90–100%.

Peak plasma concentrations are reached in 2.5–4 hours; Steady-state concentrations are attained within 2–3 days.

Distribution

Sotalol does not bind to plasma proteins. Sotalol crosses the blood brain barrier poorly.

Elimination

Renal. Half-life: 12 hours.

Betapace Interactions

Interactions

Concomitant Class IA antiarrhythmics (eg, disopyramide, quinidine, procainamide), Class III antiarrhythmics (eg, amiodarone), or other drugs that prolong QT interval: not recommended. Discontinue Class I and III antiarrhythmics for at least 3 half-lives prior to initiation. Increased risk of bradycardia or hypotension with negative chronotropes (eg, digitalis glycosides, diltiazem, verapamil, β-blockers). Hypotension, bradycardia with reserpine, guanethidine, other catecholamine-depleting drugs. Increased rebound hypertension when withdrawing clonidine. Diuretics (monitor electrolytes). Antagonizes β-agonists (eg, albuterol, terbutaline, isoproterenol). Monitor antidiabetic agents. May block epinephrine. Avoid within 2 hours of aluminum- or magnesium-containing antacids. May result in falsely elevated levels of urinary metanephrine when measured by fluorimetric or photometric methods.

Betapace Adverse Reactions

Adverse Reactions

Fatigue, bradycardia (<50bpm), dyspnea, proarrhythmia, asthenia, dizziness, headache, nausea, vomiting, diarrhea; hypotension, ventricular arrhythmias (eg, sustained VT/VF, torsade de pointes), QT prolongation.

Betapace Clinical Trials

See Literature

Betapace Note

Not Applicable

Betapace Patient Counseling

See Literature