Drug General Information (ID: DDIRKH6DMG)
Drug Name			Cyanocobalamin		Drug Info		Arsenic trioxide		Drug Info
Drug Type		Small molecule				Small molecule
Therapeutic Class		Vitamins				Antineoplastics
Structure

Mechanism of Cyanocobalamin-Arsenic trioxide Interaction (Severity Level: Moderate)
Increased risk of ventricular arrhythmias Click to Show/Hide Mechanism Graph
Drug Name		Cyanocobalamin				Arsenic trioxide
Mechanism 1		Hypokalemia				Delay atrioventricular conduction
Key Mechanism Factor 1
		Factor Name		Ventricular arrhythmias
		Factor Description		Ventricular arrhythmias are abnormal heart rhythms that cause your heart's lower chambers to pump blood instead of pumping it. This can limit or stop your heart from supplying blood to your body. While some of these arrhythmias are harmless and do not cause symptoms, others can have serious, even fatal, effects on your body.
Mechanism Description		Increased risk of ventricular arrhythmias by the combination of Cyanocobalamin and Arsenic trioxide
Mechanism 2		Hypokalemia				Prolong QT interval
Key Mechanism Factor 2
		Factor Name		Ventricular arrhythmias
		Factor Description		Ventricular arrhythmias are abnormal heart rhythms that cause your heart's lower chambers to pump blood instead of pumping it. This can limit or stop your heart from supplying blood to your body. While some of these arrhythmias are harmless and do not cause symptoms, others can have serious, even fatal, effects on your body.
Mechanism Description		Increased risk of ventricular arrhythmias by the combination of Cyanocobalamin and Arsenic trioxide

Recommended Action
Management		Caution is advised when arsenic trioxide is administered to patients requiring vitamin B12 for severe megaloblastic anemia. 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.

References
1	Product Information. Hydro-Cobex (hydroxocobalamin). Major Pharmaceuticals Inc, Rosemont, IL.
2	Product Information. Nascobol (cyanocobalamin nasal). Schwarz Pharma, Mequon, WI.
3	Product Information. Trisenox (arsenic trioxide) Cephalon Inc, West Chester, PA.