This medication is used to treat rheumatoid arthritis, a condition in which the body's own defense system (immune system) attacks healthy tissue. This leads to swelling in the joints, which causes pain and makes it harder to move. This medication is also used to treat other types of arthritis (such as juvenile idiopathic arthritis, psoriatic arthritis). Abatacept can also be used to prevent a certain problem that can occur after stem cell transplant (acute graft versus host disease).

Abatacept works by weakening your immune system. For patients with arthritis, this effect helps to slow down joint damage and reduce joint pain and swelling so that they can move better.

Read the Patient Information Leaflet if available from your pharmacist before you start using abatacept and each time you get a refill. If you have any questions, ask your doctor or pharmacist.

For the treatment of arthritis, this medication is given by injection into a vein as directed by your doctor, usually over 30 minutes. It is usually given every 2 weeks for the first 3 doses, then every 4 weeks.

For the prevention of graft versus host disease, this medication is given by injection into a vein as directed by your doctor, usually over 60 minutes. The first dose of the medication is usually given the day before transplantation and then the medication is given on days 5, 14, and 28 after transplantation. Take all other medications (such as medications to prevent infection) prescribed by your doctor exactly as directed.

The dosage is based on your medical condition and weight.

Infusion reactions may happen during the infusion of this drug and for a short time afterward. Tell your doctor right away if you have any symptoms of infusion reactions such as shortness of breath, dizziness, or headache.

Use this medication regularly to get the most benefit from it. To help you remember, mark your calendar with a reminder.

Tell your doctor if your symptoms do not get better or if they get worse.

See also How to Use section.

Headache, nausea, or cold symptoms such as stuffy head/nose may occur. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

Remember that this medication has been prescribed because your doctor has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

Because abatacept works by weakening the immune system, it may lower your ability to fight infections. This may make you more likely to get a serious (rarely fatal) infection or make any infection you have worse. Tell your doctor right away if you have any signs of infection (such as sore throat that doesn't go away, fever, chills, cough).

Rarely, patients using abatacept have developed cancer (such as lymphoma, lung/skin cancer). Tell your doctor right away if you develop symptoms such as unusual lumps/growths/skin changes, swollen glands, night sweats, unexplained weight loss, shortness of breath, wheezing.

A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including:

• rash
• itching/swelling (especially of the face/tongue/throat)
• severe dizziness
• trouble breathing

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

In the US - Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088 or at www.fda.gov/medwatch.

In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

Before using abatacept, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.

Before using this medication, tell your doctor or pharmacist your medical history, especially of:

• cancer
• chronic obstructive pulmonary disease-COPD
• current/recent/returning infection (such as tuberculosis, hepatitis)
• immune system disorder (such as HIV infection, bone marrow disorder)
• diabetes

Abatacept can make you more likely to get infections or may make current infections worse. Stay away from anyone who has an infection that may easily spread (such as chickenpox, COVID-19, measles, flu). Talk to your doctor if you have been exposed to an infection or for more details.

Tell your health care professional that you are using abatacept before having any immunizations/vaccinations. Certain types of vaccines (live vaccines) should not be given during or within 3 months after the last dose of this medication. Avoid contact with people who have recently received live vaccines (such as flu vaccine inhaled through the nose).

Children using this medication should have all recommended vaccinations before starting treatment with abatacept. Ask the child's doctor for details.

Some abatacept products are made with maltose. This substance can cause false high blood sugar levels when your blood sugar is normal or even low. If you have diabetes, ask your pharmacist if the product you are using contains maltose and if your blood sugar testing supplies will work with this product. Rarely, serious problems have occurred when too much insulin was given because of false high blood sugar readings or when low blood sugar went untreated.

Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).

During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor.

It is unknown if this medication passes into breast milk. Consult your doctor before breastfeeding.

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.

Some products that may interact with this drug include:

• anakinra
• rituximab
• TNF blocking agents (such as adalimumab, etanercept, infliximab)

This medication may interfere with certain lab tests (including certain blood sugar tests), possibly causing false test results. Make sure lab personnel and all your doctors know you use this drug.

If someone has overdosed and has serious symptoms such as passing out or trouble breathing, call 911. Otherwise, call a poison control center right away. US residents can call 1-800-222-1222. Canada residents can call 1-844-764-7669.

Lab and/or medical tests (such as tuberculosis skin test, test for hepatitis B virus, skin exams) should be done before you start taking this medication and while you are taking it. Keep all medical and lab appointments. Consult your doctor for more details.

It is important to get each dose of this medication as scheduled. If you miss a dose, ask your doctor or pharmacist right away for a new dosing schedule.

Not applicable. This medication is given in a clinic and will not be stored at home.

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-888-633-4298 (US) or 1-800-668-1507 (Canada).