Belatacept weakens your body's immune system, to help keep it from "rejecting" a transplanted organ such as a kidney. Organ rejection happens when the immune system treats the new organ as an invader and attacks it.

Belatacept is used with other medicines to prevent organ rejection after a kidney transplant. Belatacept is given only to people who have been exposed to the Epstein-Barr virus (your doctor will test your blood to confirm this).

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

Belatacept may cause your body to overproduce white blood cells. This can lead to cancer, severe brain infection causing disability or death, or a viral infection causing kidney transplant failure.

Call your doctor right away if you have: fever, swollen glands, flu symptoms, night sweats, weight loss, vomiting, diarrhea, burning when you urinate, blood in your urine, a new skin lesion, any change in your mental state, decreased vision, weakness on one side of your body, problems with speech or walking, or pain around your transplant.

Belatacept is given as an infusion into a vein. A healthcare provider will give you this injection.

Belatacept must be given slowly, and the IV infusion can take up at least 30 minutes to complete.

Belatacept is usually given just before your kidney transplant, and again 5 days later, followed by once every 2 to 4 weeks. Follow your doctor's dosing instructions very carefully.

Belatacept can increase your risk of infection by changing the way your immune system works. You will need frequent medical tests.

You should not be treated with belatacept if you are allergic to it, or if you've never been exposed to Epstein-Barr virus.

Talk with your doctor about the risks and benefits of using belatacept. Belatacept can affect your immune system, and may cause overproduction of certain white blood cells. This can lead to cancer, severe brain infection causing disability or death, or a viral infection causing kidney transplant failure.

Tell your doctor if you have ever had:

• a liver transplant;

• cytomegalovirus (CMV); or

• if you are scheduled to receive any vaccine.

It is not known whether belatacept will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

If you are pregnant, or you are a man and your sex partner is pregnant, your name may be listed on a pregnancy registry. This is to track the outcome of the pregnancy and to evaluate any effects of belatacept on the baby.

You should not breast-feed while you are using belatacept.

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

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Avoid exposure to sunlight or tanning beds. Belatacept can increase your risk of skin cancer. Wear protective clothing and use sunscreen (SPF 30 or higher) when you are outdoors.

Do not receive a "live" vaccine while using belatacept. 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), and zoster (shingles).

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

Belatacept can affect your immune system, and may cause certain white blood cells to grow out of control. Call your doctor right away if you have:

• fever, swollen glands, flu symptoms, night sweats;

• stomach pain, vomiting, diarrhea, weight loss;

• weakness on one side of your body, decreased vision, problems with speech or walking;

• memory problems, changes in your mental state;

• blood in your urine, burning when you urinate, little or no urination;

• tenderness around the transplanted kidney; or

• a new skin lesion, or a mole that has changed in size or color.

Also call your doctor at once if you have:

• low red blood cells (anemia)--pale skin, unusual tiredness, feeling light-headed or short of breath, cold hands and feet;

• high potassium--nausea, weakness, tingly feeling, chest pain, irregular heartbeats, loss of movement; or

• low potassium--leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling.

Common side effects of belatacept may include:

• high or low potassium;

• increased blood pressure;

• nausea, vomiting, diarrhea, constipation;

• kidney or bladder infection;

• headache;

• fever, cough; or

• swelling in your legs or feet.

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.

Other drugs may interact with belatacept, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.