Dose and Administration

IV

1. 0.5 to 1.5mg/kg/dose 8-hourly by slow IV infusion over 10 minutes ³

Oral

1. 1 to 2mg /kg/dose 8-hourly. Increase to 4mg/kg/dose if required ^3,6
2. Needs to be individualised

Indications

1. Supraventricular tachycardia
2. Hyperthyroidism

Contraindications

1. Cardiogenic shock.
2. Severe sinus bradycardia.
3. Congenital or acquired long QT syndromes.
4. Hypokalaemia and hypomagnesaemia.

Precautions

1. Tendency to bronchoconstriction.
2. Greater than first degree heart block
3. Heart failure
4. Renal failure – decrease the dose in renal impairment, and discontinue if renal impairment severe ³
5. Metabolic acidosis.

Drug Interactions

• Possible concomitant drug therapy should be undertaken only in consultation with paediatric cardiologist

Clinical Pharmacology

Sotalol has both beta adrenergic receptor blockade and antiarrhythmic properties. It is a non-selective beta adrenergic blocking agent affecting both beta1 and beta2 receptors. It has no intrinsic sympathomimetic activity or membrane stabilising activity. It inhibits renin release. Its beta adrenergic activity causes a reduction in heart rate (negative chronotropic effect) and a limited reduction in the force of contraction (negative inotropic effect). This leads to a decrease in myocardial oxygen consumption and cardiac work. Sotalol's antiarrhythmic activity causes a prolongation of the action potential in cardiac tissue by delaying the repolarisation phase.

When given orally its absorption is minimally affected by food. Sotalol undergoes very little first pass hepatic metabolism and, in adults, exhibits almost 100% bioavailability after oral dosing. It is not protein bound, and is hydrophilic with a low incidence of severe CNS adverse effects. Elimination is primarily by the kidneys with 75% of a dose excreted unchanged in the urine.

Possible Adverse Effects

1. Can worsen existing arrhythmias or cause new arrhythmias
2. Bradycardia, heart failure, hypotension, dyspnoea
3. Rash
4. Vomiting, diarrhoea

Special Considerations

1. Have atropine on hand for excessive bradycardia.
2. Monitor
   • Electrolytes, especially potassium and magnesium
   • QT interval. Caution if QT becomes prolonged especially with increased dosage
3. Therapeutic drug monitoring is possible.
4. Titrate dose of Sotalol when discontinuing treatment.