What side effects can this medication cause?  

Abatacept may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

• headache
• runny nose
• sore throat
• nausea
• dizziness
• heartburn
• back pain
• arm or leg pain

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:

• hives
• skin rash
• itching
• swelling of the eyes, face, lips, tongue, or throat
• difficulty breathing or swallowing
• shortness of breath
• fever, chills, and other signs of infection
• dry cough that doesn't go away
• weight loss
• night sweats
• frequent urination or sudden need to urinate right away
• burning during urination
• cellulitis (red, hot, swollen area on the skin)

Abatacept may increase the risk of developing certain types of cancer including lymphoma (cancer that begins in the cells that fight infection). People who have had severe rheumatoid arthritis for a long time may have a greater than normal risk of developing these cancers even if they do not use abatacept. Talk to your doctor about the risks of using this medication.

Abatacept may cause other side effects. Call your doctor if you have any unusual problems while using this medication.