Makindo Medical Notes

💊 Sotalol is a non-selective beta-blocker that also acts as a Class III antiarrhythmic at higher doses by prolonging cardiac action potentials. Its dual action makes it useful in arrhythmia management, but it carries important safety concerns (notably QT prolongation). Always check the BNF link here.

⚙️ Mechanism of Action

• Blocks β1 & β2 receptors → ↓ heart rate, ↓ AV conduction.
• Class III action → prolongs atrial & ventricular action potential duration.
• Can suppress ectopic activity but risks torsades if QT is prolonged.

🫀 Sotalol in Atrial Fibrillation

• Starting dose: 40 mg BD, titrated up to 160 mg BD.
• Used in paroxysmal AF, but not superior to bisoprolol in persistent AF.
• Monitor ECG: risk of QT prolongation → torsades de pointes.

📋 Indications / Dosing

• Ventricular arrhythmias, AF, SVT: 40 mg BD, ↑ to 160 mg BD orally.
• Higher doses may be required for VT suppression (specialist use only).

💊 Dose Range (check BNF/datasheet)

⚠️ Side Effects

• QT prolongation → torsades de pointes (life-threatening).
• Bradycardia, hypotension.
• Bronchospasm (β2 blockade), headache, fatigue.

🔎 Cautions

• Correct hypokalaemia & hypomagnesaemia before starting.
• Monitor ECG at initiation & dose adjustments.

🚫 Contraindications

• Asthma, bronchospasm, obstructive airway disease.
• 2nd/3rd degree AV block, HR <60/min, SBP <100 mmHg.
• Severe peripheral vascular disease, LV failure, uncontrolled CCF.

🔗 Interactions

• As per β-blockers (e.g. additive bradycardia with digoxin, amiodarone).
• Avoid with Verapamil (risk of severe bradycardia & AV block).

📖 References

• BNF: Sotalol

💡 Exam Pearls

• Think: “Beta-blocker + Class III” = dual mechanism.
• Key OSCE safety check: baseline ECG and electrolytes before starting.
• More useful in ventricular arrhythmias than in long-term AF control.