Pain/redness/swelling at the injection site, nausea, vomiting, diarrhea, stomach/abdominal pain, tiredness, cough, headache, or dizziness may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly.

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Both leukemia and this medication can lower the body's ability to fight an infection. Tell your doctor promptly if you develop any signs of an infection such as unexplained fever, chills, or persistent sore throat.

Tell your doctor immediately if any of these unlikely but serious side effects occur: easy bleeding/bruising, nosebleed, increased thirst, change in the amount of urine, blurred vision, bone/joint pain, decreased appetite, unusual weight loss, muscle pain/stiffness/spasm, numbness/tingling, swollen hands/legs/feet.

Seek immediate medical attention if any of these rare but very serious side effects occur: chest pain, severe dizziness/fainting, fast/irregular heartbeat, coughing up blood, mental/mood changes (e.g., confusion), muscle weakness, seizures, bloody/black/tarry stool, vomit that looks like coffee grounds.

A very serious allergic reaction to this drug is rare. However, seek immediate medical attention if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice any other effects not listed above, contact your doctor or pharmacist.

In the US -

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Read the Trisenox (arsenic trioxide injection) Side Effects Center for a complete guide to possible side effects »

PRECAUTIONS: Before using this medication, tell your doctor or pharmacist if you are allergic to arsenic; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially: kidney disease, diabetes.

Arsenic trioxide may cause a condition that affects the heart rhythm (QT prolongation). QT prolongation can infrequently result in serious (rarely fatal) fast/irregular heartbeat and other symptoms (such as severe dizziness, fainting) that require immediate medical attention. The risk of QT prolongation may be increased if you have certain medical conditions or are taking other drugs that may affect the heart rhythm (see also Drug Interactions section). Before using arsenic trioxide, tell your doctor or pharmacist if you have any of the following conditions: certain heart problems (heart failure, slow heartbeat, QT prolongation in the EKG), family history of certain heart problems (QT prolongation in the EKG, sudden cardiac death).

Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation. This risk may increase if you use certain drugs (such as diuretics/"water pills") or if you have conditions such as severe sweating, diarrhea, or vomiting. Talk to your doctor about using arsenic trioxide safely.

This drug may make you dizzy. Do not drive, use machinery, or do any activity that requires alertness until you are sure you can perform such activities safely. Limit alcoholic beverages.

Wash your hands well to prevent the spread of infections. Do not have immunizations/vaccinations without the consent of your doctor, and avoid contact with people who have recently received oral polio vaccine or flu vaccine inhaled through the nose.

To lower your risk of getting cut, bruised, or injured, use caution with sharp objects like razors and nail cutters, and avoid activities such as contact sports.

This drug should not be used during pregnancy. It may harm the unborn baby. If you become pregnant or think you may be pregnant, tell your doctor immediately. Talk with your doctor about effective forms of birth control.

This medication passes into breast milk. Because of the possible risk to the infant, breast-feeding while using this drug is not recommended. Consult your doctor before breast-feeding.