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Sylvant

Generic Name: siltuximab (sil TUX i mab)
Brand Name: Sylvant

Medically reviewed on August 28, 2017.

What is siltuximab?

Siltuximab inhibits a certain protein in the body called interleukin-6 (IL-6). High levels of IL-6 can cause an overgrowth of cells in the lymph system (part of your immune system).

Siltuximab is used to treat Multicentric Castleman's Disease (MCD). MCD is a rare condition in which the body produces too much of a certain type of white blood cell. MCD can increase your risk of certain cancers by changing the way your immune system works.

Siltuximab is not for use in people who have human immunodeficiency virus (HIV) or human herpesvirus-8.

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

Important Information

You should not use siltuximab if you have a severe infection. Tell your doctor if you have recently had any signs of infection (fever, chills, body aches).

Before taking this medicine

You should not use siltuximab if you are allergic to it, or if you have a severe infection.

If you have a severe illness with fever or any type of infection, you may need to wait until you get better before receiving this medicine. Tell your doctor if you have recently had any signs of infection (fever, chills, body aches).

To make sure siltuximab is safe for you, tell your doctor if you have:

  • a recent or active infection;

  • a stomach or intestinal disorder, including ulcer or diverticulitis;

  • a history of stomach or intestinal bleeding;

  • gout; or

  • if you have recently received any vaccines, or if you are due to receive one.

FDA pregnancy category C. It is not known whether siltuximab will harm an unborn baby. Siltuximab can affect the immune system of a newborn if the mother receives the medicine during pregnancy. Tell your doctor if you are pregnant or plan to become pregnant. Use effective birth control while you are using this medication and for at least 3 months after your treatment ends.

It is not known whether siltuximab passes into breast milk or if it could harm a nursing baby. You should not breast-feed while using this medicine.

How is siltuximab given?

Siltuximab is injected into a vein through an IV. A healthcare provider will give you this injection once every 3 weeks. Follow your doctor's dosing instructions very carefully.

Before each injection, your doctor may perform blood tests to make sure you do not have conditions that would prevent you from safely using siltuximab.

Siltuximab must be given slowly and the IV infusion can take at least 1 hour to complete.

Siltuximab can lower blood cells that help your body fight infections. Your blood will need to be tested often. Your siltuximab treatments may be delayed based on the results of these tests.

What happens if I miss a dose?

Call your doctor for instructions if you miss an appointment for your siltuximab injection.

What happens if I overdose?

Since this medicine is given by a healthcare professional in a medical setting, an overdose is unlikely to occur.

What should I avoid while receiving siltuximab?

Do not receive a "live" vaccine while using siltuximab. The vaccine may not work as well during this time, and may not fully protect you from disease. Live vaccines include measles, mumps, rubella (MMR), polio, rotavirus, typhoid, yellow fever, varicella (chickenpox), zoster (shingles), and nasal flu (influenza) vaccine.

Siltuximab side effects

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

Some side effects may occur during the injection. Tell your caregiver right away if you feel dizzy or light-headed, or have a chest tightness, trouble breathing, or swelling in your face.

Call your doctor at once if you have:

  • bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds;

  • signs of infection, such as fever, chills, painful mouth sores, pain when swallowing, cold or flu symptoms, cough, trouble breathing; or

  • signs of a kidney problem--little or no urinating; painful or difficult urination; swelling in your feet or ankles; severe pain in your side or lower back.

Common side effects may include:

  • weight gain;

  • itching or rash;

  • cold symptoms such as stuffy nose, sneezing, sore throat; or

  • high levels of uric acid in your blood (can lead to kidney problems or gout symptoms such as joint stiffness, pain, or swelling).

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.

See also: Side effects (in more detail)

What other drugs will affect siltuximab?

Other drugs may interact with siltuximab, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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