Pharm 101: Sotalol

Class

Class III antiarrhythmic
Beta-blocker

Pharmacodynamics

• Class III antiarrhythmic drug with both class II beta-adrenergic-receptor blocking (class II) and AP prolonging (class III) actions
• Racemic mixture of D- and L-sotalol
• L-isomer contains all of beta-adrenergic-blocking activity
• D- and L-isomers share AP prolonging effects

Pharmacokinetics

• Simple pharmacokinetics, therefore has few direct drug interactions
• Well absorbed orally, bioavailability 100%
• Low lipid solubility
• Not metabolised by liver
• Not plasma protein bound
• Half-life 12 hours
• Renal excretion of predominately unchanged form

Clinical uses

• Ventricular arrhythmias
• Maintenance of sinus rhythm in patients with AF
• Decreases threshold for cardiac defibrillation

Adverse effects

• Prolongs QT:
  • Dose-related incidence of TdP (6% at highest recommended daily dose)
• Reduction in LV function in patients with heart failure
• Acute asthma

References

• Katzung BG. Basic & Clinical Pharmacology. 14th ed. United States of America: McGraw-Hill Education; 2018. 239-244 p.