Anakinra injection is prescribed to be used alone or along with other agents in order to treat Rheumatoid Arthritis . It involves slowing down the joint damage and reduces the joint pain/swelling caused by Rheumatoid Arthritis . An anakinra injection is a man-made form of a natural protein (interleukin-1 receptor antagonist) developed by the body. It helps to inhibit the effects of another protein named interleukin-1 which can be responsible for causing joint pain/swelling/stiffness.