Sotalol Hydrochloride

Indications

Treatment of life-threatening arrhythmias including ventricular tachyarrhythmias, symptomatic non-sustained ventricular tachyarrhythmias. Prophylaxis of paroxysmal atrial tachycardia or fibrillation, paroxysmal AV re-entrant tachycardias (both nodal and involving accessory pathways), paroxysmal supraventricular tachycardia after cardiac surgery, maintenance of sinus rhythm following cardioversion of atrial fibrillation or flutter.

Pharmacology

Sotalol is a non-cardioselective beta-blocker. It increases sinus cycle length, slows heart rate, decreases AV nodal conduction and increases AV nodal refractoriness. It also prolongs AV monophasic action potentials. However, it lacks intrinsic sympathomimetic and membrane-stabilising properties.

Dosage And Administration

Initially 80 mg daily in 1-2 divided doses. After ECG monitoring and measurement of corrected QT interval, arrhythmias, dose is increased gradually at intervals of 2- 3 days to usual dose of 160-320 mg daily in 2 divided doses; higher doses of 480-640 mg daily for life-threatening ventricular arrhythmias under specialist supervision.

The dosage should be reduced in renal impairment. lf creatinine clearance is >60 ml/min, recommended dose 160 mg twice daily while in those with creatinine clearance between 40 and 60 ml/ min, the dose is administered once daily. ln patients with creatnine clearance less than 40 ml/min, Sotalol is contraindicated.

Interaction

ln combined therapy, clonidine should not be discontinued unitil several days after withdrawal of Sotalol. Use with great caution with drugs that also prolong OT interval, e.g. disopyramide, amiodarone, Class I antiarrhythmic agents, calcium antagonists of the verapamil type or tricyclic antidepressants. Interactions also occur with phenothiazines, terfenadine, astemizole and diltiazem. Concomitant use of reserpine, guanethidine, or alpha methyldopa requires close monitoring for evidence of hypotension and/or marked bradycardia, syncope. Hypoglycemia may occur and the dosage of insulin or antidiabetic drugs may require adjustment.

Contraindications

Sotalol should not be given to patients with sinus, bradycardia, sick sinus syndrome or second or third degree AV block (unless a functional pacemaker is present); congenital or acquired long QT syndromes, torsades de pointes, uncontrolled congestive heart failure, cardiogenic shock; anaesthesia that produces myocardial depression, hypotension (except due to arrhythmia), severe peripheral circulatory disturbances, chronic obstructive airway disease or bronchial asthma, renal failure (ceratinine clearance <40mL/min) and previous evidence of hypersensitivity to Sotalol. Sotalol should not be given to patients suffering from diabetic keto-acidosis or metabolic acidosis, therapy with Sotalol can be recommenced or resumed when the metabolic condition has been corrected.

Side Effects

The most significant adverse effects are those which are typical of its class I and class II (Cardiac action potential duration prolongation) effects.

Pregnancy And Lactation

Its use throughout pregnancy should be avoided unless it is absolutely necessary as it crosses the placenta and may cause foetal bardycardia. Infants should not be fed with breast milk from mothers being treated with Sotalol.

Precautions And Warnings

Sotalol is not for everyone with irregular heartbeats (atrial fibrillation). Sotalol is not indicated for those patients who have serious kidney problems or are on kidney dialysis, lung disease causing shortness of breath (such as asthma, chronic bronchitis or emphysema), symptoms of heart failure (such as shortness of breath when in exercise or physically active and swelling of the ankles or legs), very slow heart beat and do not have an implanted artificial pacemaker.

Overdose Effects

Overdosage causes excessive bradycardia and hypotension; congestive heart failure, bronchospasm and hypoglycemia.

Therapeutic Class

Anti adrenergic agent (Beta blockers).

Storage Conditions

Store in a cool and dry place, protected from light.