Which medication class is associated with an increased risk of torsades de pointes?

Which medication class is associated with an increased risk of torsades de pointes?

• A. Antiarrhythmics such as amiodarone and sotalol
• B. Beta blockers
• C. ACE inhibitors
• D. Calcium supplements

Answer: (A)

Torsades de pointes is most likely to occur when the heart’s repolarization is slowed, causing a prolonged QT interval on the ECG. Drugs that block potassium channels and delay repolarization push the QT interval longer, raising the risk of this dangerous rhythm. Antiarrhythmic medicines that affect repolarization are the class linked to this risk, with amiodarone and sotalol as typical examples. Sotalol, a potassium-channel blocker with beta-blocking effects, directly lengthens the QT interval and can trigger torsades, especially if electrolytes are imbalanced or bradycardia is present. Amiodarone also prolongs QT, though it tends to carry a lower torsades risk compared with other QT-prolonging drugs because of its broad actions across multiple ion channels; nonetheless, the risk isn’t zero, particularly in predisposed patients or with interacting medications. In contrast, beta blockers, ACE inhibitors, and calcium supplements do not appreciably prolong the QT interval and are not typically associated with torsades de pointes, so they’re not the drugs linked to this specific danger.

Torsades de pointes is most likely to occur when the heart’s repolarization is slowed, causing a prolonged QT interval on the ECG. Drugs that block potassium channels and delay repolarization push the QT interval longer, raising the risk of this dangerous rhythm.

Antiarrhythmic medicines that affect repolarization are the class linked to this risk, with amiodarone and sotalol as typical examples. Sotalol, a potassium-channel blocker with beta-blocking effects, directly lengthens the QT interval and can trigger torsades, especially if electrolytes are imbalanced or bradycardia is present. Amiodarone also prolongs QT, though it tends to carry a lower torsades risk compared with other QT-prolonging drugs because of its broad actions across multiple ion channels; nonetheless, the risk isn’t zero, particularly in predisposed patients or with interacting medications.

In contrast, beta blockers, ACE inhibitors, and calcium supplements do not appreciably prolong the QT interval and are not typically associated with torsades de pointes, so they’re not the drugs linked to this specific danger.