Enbrel, generic name Etanercept, relieves the pain, swelling and inflammation of rheumatoid arthritis and other autoimmune disorders. Enbrel, a laboratory manufactured protein, is a tumor-necrosis factor, or TNF inhibitor. Enbrel blocks TNF, a substance involved in inflammation and immune system responses. People with rheumatoid arthritis, or RA, have higher than normal levels of TNF in their blood, which cause increased pain and swelling in joints. Although Enbrel is effective, it can produce serious side effects.
Mechanism
Side effects from Enbrel occur because the drug interrupts the normal immune system response. As a result, people taking Enbrel, especially if they are taking other medications that interfere with the immune system such as steroids, may have increased risk of infection, tuberculosis and certain cancers. The FDA added a "black box" warning to Enbrel--and other similar medication--related to the increased risk of infections and cancers, the National Institutes of Health reports.
Types
Many different side effects can occur in people taking Enbrel for rheumatoid arthritis, including increased risk for pneumonia, skin infections, kidney infections and upper respiratory infections. Enbrel can increase the risk of tuberculosis, with most cases being reactivations of previous infection, R.W. Jackson, D.O. of A.T. Still University reports. People with active tuberculosis should not take Enbrel, Jackson warns. Lymphoma, cancer of the lymph system, occurred three times as often in people taking Enbrel as in the general population in one large clinical, according to Drugs.com. Injection site reactions occurred in 37 percent of people receiving Enbrel for rheumatic disease and new development of antinuclear antibodies, often seen in autoimmune diseases such as lupus, occurred in 11 percent of people.
Positive Side Effects
Enbrel may have positive benefits for people with rheumatoid arthritis beyond disease improvement. At the 2006 European Congress of Rheumatology, Dr. Will G. Dixon of the University of Manchester reported a 72 percent reduction in heart attacks and a 49 percent reduction in strokes, possibly due to reduced inflammation in cells.
Limiting Side Effects
To limit side effects in especially susceptible populations, some people, such as pregnant women or those trying to get pregnant should not take Enbrel. Live vaccines should not be given to people receiving Enbrel, although killed vaccines should be given to prevent influenza and pneumonia. Stopping Enbrel one week before surgery helps prevent the risk of infection. People receiving cancer treatment should also not take Enbrel.
Weighing Risks and Benefits
Enbrel's side effects can be serious, but the pain, deformity and disability of rheumatoid arthritis can also have serious negative effects on a person's life. Regular medical evaluation and blood tests to watch for development of side effects helps maximize the benefit and reduce risks.
