Sotalol hydrochloride

Dose and administration

IV

0.5 to 1.5mg/kg/dose 8-hourly by slow IV infusion over 10 minutes³

Oral

• 1 to 2mg /kg/dose 8-hourly. Increase to 4mg/kg/dose if required³,⁶ 

• 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 severe³

5. Metabolic acidosis.

Drug interactions

Amiodarone: Bradycardia and hypotension (mechanism not established). Monitor for haemodynamic depression

Diuretics: May induce hypokalaemia or hypomagnesemia therefore increasing the risk of Torsades de Pointes

Flecainide: Bradycardia, AV block, cardiac arrest (allow a gap of several days before starting flecainide)

Chlorpromazine: Hypotension

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:

   1. Electrolytes, especially potassium and magnesium 

   2. 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.

Management of Sotolol administration

Description

IV preparation: Clear, colourless solution 10mg/ml in 4ml ampoules. No antibacterial agent.

Oral preparation: During Pharmacy hours scan drug chart to Pharmacy for dispensing. Outside Pharmacy hours, contact Ward 23B (Starship Hospital) for their stock bottle of oral Sotalol liquid.

Prescription

• Individual doses are charted on stat page of prescription chart in mg/dose.

• Maintenance doses are charted on the prescription chart in mg/dose.

Administration

Slow IV Infusion

1. Dilute immediately prior to use to 1mg/ml by adding to sodium chloride 0.9% or glucose 5% .

2. Filter prior to administration through a 5 micron filter needle.

3. Administer by slow IV infusion over 10 minutes using a syringe pump.

4. Compatible with sodium chloride 0.9% or glucose 5%. Do not mix with other drugs or IV solutions

5. Flush line with sodium chloride 0.9% before and after infusion of Sotalol.

Oral

1. Follow instructions on bottle.

2. Is preferable to administer before food⁶. Be consistent when administering with or without food.

3. Do not administer with calcium containing products.

Observation and documentation

1. Assess for signs of adverse reactions.

2. Cardiorespiratory monitoring during acute usage. Report and record changes in heart rate and rhythm.

3. Monitor blood pressure.

4. Document vital signs.

5. Document baby's response to medication.

Storage

IV preparation: Unopened. Store at room temperature <25°C.