Etanercept, a biologic tumor necrosis factor (TNF) antagonist, is a recombinant human TNF receptor p75 fusion protein that inhibits proinflammatory cytokine activity. It is prescribed, either alone or in combination with methotrexate, to reduce the signs and symptoms of rheumatoid arthritis (RA) and to slow the progression of joint damage in patients with moderately to severely active disease.