Drug Interaction Report

Arsenic trioxide can cause an irregular heart rhythm that may be serious and potentially life-threatening, and the risk may be increased during treatment with cyanocobalamin for severe anemia. As your body responds to the replenishment of vitamin B12, potassium from the blood is used to generate more red blood cells. This can lead to a condition known as hypokalemia, or low blood potassium. In severe cases, hypokalemia can cause irregular heart rhythm, as well as other problems such as muscle weakness, paralysis, and breathing and swallowing difficulties (due to muscle paralysis). Talk to your doctor if you have any questions or concerns. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Let your doctor know if you experience nausea, vomiting, constipation, abdominal cramping, confusion, dizziness, lightheadedness, fainting, muscle weakness, muscle cramps, numbness, tingling, rapid heartbeat, chest pain, and/or swelling in the legs or feet, as these may be symptoms of hypokalemia. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

Arsenic trioxide can cause an irregular heart rhythm that may be serious and potentially life-threatening, and the risk may be increased during treatment with methylcobalamin for severe anemia. As your body responds to the replenishment of vitamin B12, potassium from the blood is used to generate more red blood cells. This can lead to a condition known as hypokalemia, or low blood potassium. In severe cases, hypokalemia can cause irregular heart rhythm, as well as other problems such as muscle weakness, paralysis, and breathing and swallowing difficulties (due to muscle paralysis). Talk to your doctor if you have any questions or concerns. You may need a dose adjustment or more frequent monitoring by your doctor to safely use both medications. Let your doctor know if you experience nausea, vomiting, constipation, abdominal cramping, confusion, dizziness, lightheadedness, fainting, muscle weakness, muscle cramps, numbness, tingling, rapid heartbeat, chest pain, and/or swelling in the legs or feet, as these may be symptoms of hypokalemia. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.