What is Abatacept?

Abatacept is an immune system modulating medication used to treat rheumatoid arthritis (RA) and severe polyarticular juvenile idiopathic arthritis (JA) in some children over the age of six. The medication works by blocking the activity of the thymus cells (T-cells) of the immune system. Called a T-cell co-stimulation medication, abatacept lowers the immune system response that attacks the lining of the joints, relieving pain and swelling.

This arthritis medication is not absorbed by the body when taken orally. The medication is injected or administered through an intravenous (IV) line in a process that usually takes about 30 minutes. After the first dose of the medicine, a second and third dose usually is given at two-week intervals. Any following doses are given every four weeks thereafter.

The immune system is significantly hindered while taking abatacept, so the medicine is not given to people with a current infection or an open wound. Before prescribing it, most physicians usually test the patient for any serious illnesses, such as hepatitis or tuberculosis (TB). As the immune system has difficulty functioning properly while a person is taking this arthritis treatment, people who take this medicine have an increased risk of coming down with a serious respiratory infection, such as pneumonia, and may have a harder time healing from infections.

Physicians usually prescribe abatacept after other rheumatoid arthritis medications have failed to give a patient any relief from his symptoms. Abatacept has been successful at reducing the immune response that causes painful joint damage and for helping relieve the pain that prevents many with RA from completing regular daily activities. If treatment is begun early after diagnosis, this medication may prevent the distortion to the joints affected by RA.

The most common side effect of abatacept is an increased risk of an acquired infection and difficulty healing from current infections. Some patients report nausea and vomiting after an infusion of the medication. Most often, people report headaches after the medicine is taken. There are some indications of an increased risk of developing cancer while taking the medication as well.

Some people are not good candidates for treatment with abatacept. Scientists do not know if it is passed to the fetus of a pregnant woman or if the medicine is secreted in breast milk. As such, abatacept is not recommended for use by pregnant or nursing women. It is also contraindicated in some cases of kidney or liver disease.