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Medications and Drugs

Brand Names: Bexxar Dosimetric, BexxarTherapeutic

Generic Name: tositumomab (Pronunciation: TOE si too MOE mab)

What is tositumomab (Bexxar Dosimetric, BexxarTherapeutic)?

Tositumomab is a monoclonal antibody that is linked with radioactive iodine I-131. Monoclonal antibodies are made to target and destroy only certain cells in the body. This may help to protect healthy cells from damage.

Tositumomab is used to treat certain forms of non-Hodgkin's lymphoma. It is usually given after other medications have been tried without successful treatment.

Tositumomab may also be used for purposes not listed in this medication guide.

What are the possible side effects of tositumomab (Bexxar Dosimetric, BexxarTherapeutic)?

Some people receiving a tositumomab injection have had a reaction to the infusion (when the medicine is injected into the vein). Tell your caregiver right away if you feel dizzy, nauseated, light-headed, sweaty, or short of breath, or if you have fever or chills during the injection.

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Call your doctor at once if you have a serious side effect such as:

  • pale skin, feeling light-headed or short of breath, rapid heart rate, trouble concentrating;
  • easy bruising, unusual bleeding (nose, mouth, vagina, or rectum), purple or red pinpoint spots under your skin;
  • fever, chills, sore throat, body aches, flu symptoms;
  • blood in your urine or stools, coughing up blood or vomit that looks like coffee grounds; or
  • stabbing chest pain, wheezing, cough with yellow or green mucus; feeling short of breath.

Less serious side effects may include:

  • decreased energy, feeling weak or irritable;
  • weight gain;
  • headache, joint or muscle pain;
  • increased thirst and hot, dry skin;
  • nausea, vomiting, diarrhea, stomach pain, loss of appetite;
  • mild itching or skin rash;
  • runny or stuffy nose; or
  • pain, itching, swelling, or redness around the IV needle.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What is the most important information I should know about tositumomab (Bexxar Dosimetric, BexxarTherapeutic)?

You should not receive this medication if you are allergic to mouse proteins, or if you have ever had an allergic reaction to a monoclonal antibody.

Before you receive tositumomab, tell your doctor if you have kidney disease or severe bone marrow suppression.

Tositumomab can cause damage to the thyroid gland of an unborn baby if the mother receives this medication during pregnancy. You should not receive this medication if you are pregnant.

Tositumomab can be harmful to an unborn baby whether the father or the mother receives this medication at the time of conception. Use effective birth control to prevent pregnancy during your treatment, whether you are a man or a woman. Continue using birth control for at least 12 months after you have received tositumomab.

Tositumomab can lower blood cells that help your body fight infections. Your blood may need to be tested often. Avoid being near people who are sick or have infections. Avoid activities that may increase your risk of bleeding injury. Tell your doctor at once if you develop signs of infection.

Do not receive a "live" vaccine just after you receive tositumomab.

After you are treated with tositumomab, your body will retain radioactive material for several days. During this time you will be giving off a small amount of radiation to others around you. Your caregivers should give you instructions about how to avoid exposing other people to radiation until this effect wears off. Follow these instructions carefully.

Take all medications your doctor prescribes to help protect your thyroid gland when you receive tositumomab. You may need to have blood tests to check your thyroid function at regular intervals for the rest of your life. Visit your doctor regularly.

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

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