Q: 78 year old DNR patient is in Atrial fibrillation with RVR (Rapid Ventricular Rate) causing borderline hypotension. Patient did not respond to Digoxin and Amiodarone. Patient is on chronic coumadin therapy with INR of 2.8. Echo ruled out any thrombus. Patient refuses any sort of cardioversion but oked any drug treatment. Cardiologist on consult informed you that he will be using ibutalide this afternoon to see if that works. To minimize the associated ventricular arrhythmia what could be your preventive strategy?

Answer: Administer Magnesium before ibutalide use

The risk of developing torsade de pointes with ibutilide is about 4% but it can reduced with intravenous infusion of high-dose magnesium sulfate and having potassium level around 4.5 range.

Reference: Patsilinakos S, Christou A, Kafkas N, et al. Effect of high doses of magnesium on converting ibutilide to a safe and more effective agent. Am J Cardiol 2010; 106: 673–6