Which drug is dosed as 2 g IV/IO in 10 mL NS over 2 minutes in torsades de pointes?

Which drug is dosed as 2 g IV/IO in 10 mL NS over 2 minutes in torsades de pointes?

• A. Amiodarone
• B. Lidocaine
• C. Adenosine
• D. Magnesium sulfate

Answer: (D)

Torsades de pointes is a form of ventricular tachycardia that is strongly linked to prolonged QT and the presence of early afterdepolarizations that trigger the rapid, irregular rhythm. The fastest and most reliable way to interrupt this rhythm is to give magnesium, which helps stabilize the cardiac membranes and suppress those early depolarizations that drive the torsades arrhythmia, even if the patient’s magnesium level is not low. The dosing in this scenario—2 grams given IV or IO in 10 mL of normal saline over about 2 minutes—provides a rapid, effective dose to quickly exert its stabilizing effect. If the arrhythmia recurs, the dose can be repeated, and an infusion may be considered if ongoing suppression is needed. Other drugs listed do not address the underlying mechanism of torsades. Amiodarone is used for other ventricular or atrial arrhythmias but is not the preferred first-line treatment for torsades specifically. Lidocaine is more suited for certain ischemia-related VT, not torsades. Adenosine is used for certain supraventricular tachycardias and does not treat torsades.

Torsades de pointes is a form of ventricular tachycardia that is strongly linked to prolonged QT and the presence of early afterdepolarizations that trigger the rapid, irregular rhythm. The fastest and most reliable way to interrupt this rhythm is to give magnesium, which helps stabilize the cardiac membranes and suppress those early depolarizations that drive the torsades arrhythmia, even if the patient’s magnesium level is not low. The dosing in this scenario—2 grams given IV or IO in 10 mL of normal saline over about 2 minutes—provides a rapid, effective dose to quickly exert its stabilizing effect. If the arrhythmia recurs, the dose can be repeated, and an infusion may be considered if ongoing suppression is needed.

Other drugs listed do not address the underlying mechanism of torsades. Amiodarone is used for other ventricular or atrial arrhythmias but is not the preferred first-line treatment for torsades specifically. Lidocaine is more suited for certain ischemia-related VT, not torsades. Adenosine is used for certain supraventricular tachycardias and does not treat torsades.