Drug Interactions between arsenic trioxide and digoxin immune fab

MONITOR CLOSELY: Arsenic trioxide can cause QT interval prolongation and complete atrioventricular block. Since hypokalemia and hypomagnesemia are known risk factors for arrhythmia associated with QT prolongation, coadministration of arsenic trioxide with agents that can cause significant potassium and/or magnesium loss (e.g., potassium-wasting diuretics, amphotericin B, cation exchange resins) may increase the risk of ventricular arrhythmias such as torsade de pointes and sudden death.

MANAGEMENT: Caution is advised if arsenic trioxide must be used concomitantly with medications that can cause significant potassium and/or magnesium loss. Serum electrolytes should be evaluated and any abnormalities corrected prior to initiating therapy with arsenic trioxide. During therapy, potassium concentrations should be kept above 4 mEq/dL and magnesium concentrations above 1.8 mg/dL. Patients should also have frequent ECGs and be monitored for serious arrhythmias when QT intervals are prolonged. Patients should be advised to seek medical attention if they experience symptoms that could indicate the occurrence of torsade de pointes such as dizziness, palpitations, or syncope.