Arsenic Trioxide (Trisenox®)

OncoLink Team
Last Modified: July 23, 2015

Pronounced: AR-se-nik trye-OX-ide

Classification: Antineoplastic Agent

About Arsenic Trioxide

Arsenic trioxide is a form of the naturally occurring compound arsenic. It has been used by health practitioners (particularly in Asia) for hundreds of years. It is safe when given in small doses by experienced healthcare professionals. It seems to work against cancer by causing cancer cells to self-destruct; this is also known as apoptosis.

How to Take Arsenic Trioxide

Arsenic trioxide is given by intravenous (into a vein) infusion over 1-2 hours.  Treatment time can be extended to four hours for those who have an infusion reaction such as rash, shortness of breath, and cough. Your specific dose will depend on your body size.

Possible Side Effects

There are a number of things you can do to manage the side effects of arsenic trioxide. Talk to your doctor or nurse about these recommendations. They can help you decide what will work best for you. These are some of the most common side effects:

Differentiation Syndrome

This is a syndrome resulting from the changes arsenic trioxide causes to blood cell production in patients with leukemia. Symptoms of differentiation syndrome include: fever (temperature >100.5), sudden weight gain, bone or joint pain, and fluid build-up around the heart, lungs, and/or chest, causing shortness of breath or difficulty breathing. This syndrome is treated with high doses of steroids (like prednisone) and diuretics (fluid pills). Your healthcare providers will monitor for these signs or symptoms, but it is also important for you to tell your doctor or nurse promptly if you experience any of these symptoms. You will be asked to weigh yourself every day during the first few weeks of therapy, and to report any increases in weight.

Heart Issues

This medication can cause slow or abnormal heartbeats or an abnormal heart rhythm called QT prolongation. Notify your healthcare provider right away if you feel abnormal heartbeats or if you feel dizzy or faint.

High Blood Sugar

This medication can cause elevated blood sugar levels in patients with and without diabetes. Your healthcare team will monitor your blood sugar. If you develop increased thirst, urination or hunger, blurry vision, headaches or your breath smells like fruit, notify your healthcare team. Diabetics should monitor their blood sugar closely and report elevations to the healthcare team.

Allergic Reactions

In some cases, patients can have an allergic reaction to this medication. Signs of a reaction can include: shortness of breath or difficulty breathing, chest pain, rash, flushing or itching or a decrease in blood pressure. If you notice any changes in how you feel during the infusion, let your nurse know immediately. The infusion will be slowed or stopped if this occurs. Depending on the severity of your reaction, you may still be able to receive the medication with a pre-medication to prevent a reaction, or if the medication is given at a slower rate.


Your doctor or nurse can recommend medication and other strategies to relive pain.

Leukocytosis (high white blood cell count)

This drug can impact your white blood cell counts.  Generally, it does not cause any problems, nor does it require stopping the treatment. Your healthcare provider will monitor your white blood count during treatment.

Nausea and/or Vomiting

Talk to your doctor or nurse so they can prescribe medications to help you manage nausea and vomiting. In addition, dietary changes may help. Avoid things that may worsen the symptoms, such as heavy or greasy/fatty, spicy or acidic foods (lemons, tomatoes, oranges). Try antacids, (e.g. milk of magnesia, calcium tablets such as Tums), saltines, or ginger ale to lessen symptoms.

Call your doctor or nurse if you are unable to keep fluids down for more than 12 hours or if you feel lightheaded or dizzy at any time.


Your oncology team can recommend medications to relieve diarrhea. Also, try eating low-fiber, bland foods, such as white rice and boiled or baked chicken. Avoid raw fruits, vegetables, whole grain breads, cereals and seeds. Soluble fiber is found in some foods and absorbs fluid, which can help relieve diarrhea. Foods high in soluble fiber include: applesauce, bananas (ripe), canned fruit, orange sections, boiled potatoes, white rice, products made with white flour, oatmeal, cream of rice, cream of wheat, and farina. Drink 8-10 glasses on non-alcoholic, un-caffeinated fluid a day to prevent dehydration.


Fatigue is very common during cancer treatment and is an overwhelming feeling of exhaustion that is not usually relieved by rest. While on cancer treatment, and for a period after, you may need to adjust your schedule to manage fatigue. Plan times to rest during the day and conserve energy for more important activities. Exercise can help combat fatigue; a simple daily walk with a friend can help.  Talk to your healthcare team for helpful tips on dealing with this side effect.

Secondary Malignancy

This drug is a carcinogen; therefore there is a risk of developing another other type of cancer as a result of treatment.  This can occur many years after treatment.  Your healthcare team will plan cancer screening and monitoring for secondary malignancy accordingly.

Peripheral Neuropathy

Peripheral neuropathy is a toxicity that affects the nerves. It causes a numbness or tingling feeling in the hands and feet, often in the pattern of a stocking or glove. This can get progressively worse with additional doses of the medication. In some people, the symptoms slowly resolve after the medication is stopped, but for some it never goes away completely. You should let your healthcare provider know if you experience numbness or tingling in the hands and feet, as they may need to adjust the doses of your medication.

Edema (Swelling)

This medication can cause swelling. If you experience, rapid weight gain or swelling in your legs or feet, notify your oncology team.

Cough and Dyspnea (shortness of breath)

You may experience a cough or shortness of breath while taking this medication.


Some patients may develop a rash, scaly skin, or red itchy bumps. Use an alcohol free moisturizer on your skin and lips; avoid moisturizers with perfumes or scents. Your doctor or nurse can recommend a topical medication if itching is bothersome. If your skin does crack or bleed, be sure to keep the area clean to avoid infection. Be sure to notify your healthcare provider of any rash that develops, as this can be a reaction. They can give you more tips on caring for your skin.

Electrolyte abnormalities

This medication can impact levels of some electrolytes.  Your healthcare team will routinely monitor your blood counts and electrolyte levels.

Reproductive Concerns

Exposure of an unborn child to this medication could cause birth defects, so you should not become pregnant or father a child while on this medication. Effective birth control for men and women is necessary during and after treatment. Even if your menstrual cycle stops or you believe you are not producing sperm, you could still be fertile and conceive. You should consult with your healthcare team before breastfeeding while receiving this medication.


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