Sotalol

1. Introduction

Sotalol is a non-selective beta-blocker with Class III antiarrhythmic properties used primarily for the treatment of ventricular and supraventricular arrhythmias, including atrial fibrillation. It works by blocking beta-adrenergic receptors and inhibiting potassium channels, which slows heart rate and prolongs cardiac repolarisation.

2. Indications

  • Atrial Fibrillation (AF) and Atrial Flutter: Prevention and maintenance of normal sinus rhythm.
  • Ventricular Arrhythmias: Prevention of life-threatening ventricular tachycardia (VT) and ventricular fibrillation (VF).
  • Supraventricular Tachycardia (SVT): Rate control and prevention of recurrence.

3. Dosage

Adults:

  • Atrial Fibrillation/Atrial Flutter:
    • Initial: 80 mg twice daily.
    • May increase to 160–240 mg/day based on response and tolerance.
    • Maximum dose: 320 mg/day in divided doses.
  • Ventricular Arrhythmias:
    • Initial: 80 mg twice daily.
    • Can be titrated up to 320 mg/day in divided doses (in severe cases, up to 480 mg/day under specialist supervision).

Elderly:

  • Start at the lowest effective dose, monitoring renal function.

Children:

  • 1 mg/kg/dose twice daily, adjusted based on response and ECG monitoring.

Renal Impairment:

  • CrCl 30–59 mL/min: Reduce dose or extend dosing interval (e.g., every 24 hours instead of 12).
  • CrCl <30 mL/min: Avoid use.

Hepatic Impairment:

  • No dose adjustment required.

4. Administration

  • Take orally, preferably on an empty stomach (1 hour before or 2 hours after food).
  • Do not crush or chew extended-release tablets.
  • Dose adjustment should be made under ECG monitoring.

5. Forms Available

  • Tablets: 80 mg, 120 mg, 160 mg
  • Injectable solution: 150 mg/10 mL (IV use)

6. Side Effects

6.1 Common Side Effects:

  • Fatigue
  • Dizziness
  • Bradycardia (slow heart rate)
  • Hypotension (low blood pressure)

6.2 Less Common Side Effects:

  • Shortness of breath (due to beta-blockade in patients with asthma/COPD)
  • Cold extremities
  • Nausea

6.3 Rare but Serious Side Effects:

  • Torsades de Pointes (life-threatening ventricular arrhythmia)
  • QT prolongation
  • Worsening heart failure
  • Severe hypotension
  • Hypoglycaemia (especially in diabetics)

7. Warnings

  • QT Prolongation & Torsades de Pointes: Risk increases with higher doses, electrolyte imbalances (hypokalaemia, hypomagnesaemia), and renal impairment.
  • Heart Failure & Bradycardia: May worsen symptoms of heart failure and cause excessive heart rate slowing.
  • Asthma & COPD: May trigger bronchospasm due to non-selective beta-blockade.
  • Renal Impairment: Sotalol is renally excreted; adjust dose accordingly.

8. Precautions

  • Monitor serum electrolytes (potassium, magnesium) before and during therapy.
  • Avoid abrupt discontinuation, as it may lead to rebound tachycardia or worsening arrhythmias.
  • Use cautiously in elderly patients due to an increased risk of hypotension and bradycardia.

9. Interactions

  • QT-prolonging drugs (e.g., amiodarone, macrolides, fluoroquinolones): Increased risk of Torsades de Pointes.
  • Calcium Channel Blockers (e.g., verapamil, diltiazem): Risk of excessive bradycardia or hypotension.
  • Diuretics (e.g., furosemide, hydrochlorothiazide): Risk of electrolyte imbalances that may worsen QT prolongation.
  • Beta-agonists (e.g., salbutamol): Reduced bronchodilator effect due to beta-blockade.
  • Insulin & Oral Hypoglycaemics: May mask signs of hypoglycaemia.

10. Monitoring Parameters

  • ECG monitoring: Before and during treatment to assess QT interval.
  • Heart rate & blood pressure: Regular monitoring required.
  • Electrolytes (potassium, magnesium): To prevent arrhythmias.
  • Renal function (CrCl): Adjust dose accordingly.

11. Use in Children

  • Used in paediatric patients for arrhythmias, but requires specialist supervision.
  • Dose based on weight, with ECG monitoring required.

12. Use in Pregnancy

  • Category B: Use only if potential benefits outweigh risks. Limited data on foetal effects.

13. Use in Elderly

  • Use with caution; increased risk of bradycardia, hypotension, and renal impairment.

14. Use in Kidney Disease

  • Dose adjustment required for CrCl <60 mL/min.
  • Contraindicated in severe renal impairment (CrCl <30 mL/min).

15. Use in Liver Disease

  • No dose adjustment required, as sotalol is renally excreted.

16. Patient Counselling Points

  • Take sotalol exactly as prescribed, preferably on an empty stomach.
  • Do not stop suddenly; consult a doctor if discontinuation is necessary.
  • Avoid over-the-counter decongestants (e.g., pseudoephedrine) as they may worsen arrhythmias.
  • Report any dizziness, fainting, palpitations, or shortness of breath immediately.
  • Keep hydrated and avoid electrolyte imbalances, as they increase arrhythmia risk.

17. Table of Brand Names, Manufacturer, and Prices in USD

Brand NameManufacturerStrength/Dosage FormPrice (USD)
BetapaceBayer80 mg Tablet$50 (30 tablets)
SotalexSanofi120 mg Tablet$70 (30 tablets)
Generic SotalolVarious80 mg Tablet$20 (30 tablets)

18. 15 FAQs (Frequently Asked Questions)

1. What is Sotalol used for?
Sotalol is used to treat atrial fibrillation, ventricular arrhythmias, and supraventricular tachycardia.

2. How does Sotalol work?
It blocks beta-adrenergic receptors and inhibits potassium channels, slowing heart rate and prolonging repolarisation.

3. Can Sotalol cause dizziness?
Yes, dizziness is a common side effect due to its effects on heart rate and blood pressure.

4. Can Sotalol be stopped suddenly?
No, stopping abruptly may cause rebound arrhythmias or tachycardia.

5. Does Sotalol require ECG monitoring?
Yes, ECG monitoring is essential due to the risk of QT prolongation.

6. Can Sotalol be taken with food?
It is best taken on an empty stomach, as food may reduce absorption.

7. Can Sotalol cause low blood pressure?
Yes, hypotension is a possible side effect.

8. Can Sotalol cause breathing problems?
Yes, it may worsen asthma or COPD due to beta-blockade.

9. Is Sotalol safe during pregnancy?
Use only if the benefits outweigh the risks, as safety data is limited.

10. Can Sotalol be used in kidney disease?
Yes, but dose adjustments are required for CrCl <60 mL/min.

11. How long does Sotalol take to work?
It starts working within hours, but full effects may take several days.

12. Can Sotalol cause depression?
Beta-blockers like sotalol have been associated with mood changes in some patients.

13. Can I drink alcohol with Sotalol?
Alcohol may enhance dizziness or hypotension; limit consumption.

14. Can Sotalol be taken with digoxin?
Yes, but close monitoring is required due to potential bradycardia.

15. How should Sotalol be stored?
Store at room temperature, away from moisture and heat.