Tumor necrosis factor is a protein in your body that causes inflammation. TNF inhibitors are drugs that help stop inflammation and are used worldwide to treat inflammatory conditions such as rheumatoid arthritis (RA), psoriatic arthritis, juvenile arthritis, inflammatory bowel disease (Crohn’s and ulcerative colitis), ankylosing spondylitis, and psoriasis. They reduce inflammation and can stop disease progression by targeting an inflammation-causing substance called Tumor Necrosis Factor (TNF).
In healthy individuals, excess TNF in the blood is blocked naturally, but in those who have rheumatic conditions, higher levels of TNF in the blood lead to more inflammation and persistent symptoms. These medications can alter a disease’s effect on the body by controlling inflammation in the joints, gastrointestinal tract, and skin.
The TNF inhibitors that have been approved by the FDA include infliximab, adalimumab, etanercept, golimumab, and certrolizumab. To decrease side effects and costs, most patients with mild or moderate disease are treated with methotrexate before adding or switching to a TNF inhibitor. These agents can be used by themselves or in combination with other medications such as prednisone, methotrexate, hydroxychloroquine, leflunomide or sulfasalazine.
TNF inhibitors may be given by injection under the skin or by infusion into the vein. There are pamphlets and videos that can teach you how to give yourself an injection under the skin. Physicians, nurses, and pharmacists can also teach you how to give the injection. The medicine can be injected into the skin of the thigh or abdomen. The site of injection should be rotated so the same site is not used multiple times. Infliximab and golimumab infusions are administered at a doctor’s office or an infusion center. These treatments take up to 4 hours. The time that it takes for the medication to have an effect may vary by patient. Most patients have reported a change in their symptoms after 2 or 3 doses, but it usually takes 3 months to see the full benefit.
The most common side effect seen with the injectable drugs are skin reactions, commonly referred to as “injection site reactions.” These reactions can last up to a week. Infliximab, which is only available as an intravenous infusion injected directly into a vein has been associated with a severe allergic reaction with swelling of the lips, difficulty breathing and low blood pressure. The most significant side effects for all of the TNF inhibitors is an increased risk for all types of infections, including tuberculosis (TB) and fungal infections. Some of these infections may be severe. Patients should be tested for TB before starting therapy, because TB infection can worsen. The usual way of testing is with a skin test, but a blood test is also available. A new study finds that taking TNF inhibitor biologics does not increase the risk of developing a new cancer, nor does it increase risk in cancer survivors.(1) Recent studies are unable to confirm an increased risk of melanoma (a type of skin cancer) with anti-TNF inhibitors. The risk of non-melanoma skin cancer may be increased in patients who receive TNF inhibitors; however, the risk may be increased in all patients with rheumatoid arthritis regardless of treatment. Thus, general screening for skin cancer in patients with RA should be performed to identify potential skin cancers. There are rare neurologic complications as well. People who have a history of multiple sclerosis should not take these medications. People with significant heart failure should not use a TNF inhibitor, because their heart disease could worsen.
TNF inhibitors are usually held if the patient has high fever or is being treated with antibiotics for an infection. Once the infection goes away, the medication can be restarted.
Patients should talk to their rheumatology provider before getting any vaccinations while using an anti-TNF drug. Some vaccinations are safe, but live vaccines should be avoided.
These medications are expensive (more than $10,000 per year), but they are covered by most health care insurance plans. Copay amounts vary widely. Ask your rheumatology provider about prescription assistance plans that can help you to get the medication at a lower price or free of charge. Refer to the package insert for more information.
Updated December 2020 by Senada Arabelovic, DO, and reviewed by the American College of Rheumatology Committee on Communications and Marketing.
This information is provided for general education only. Individuals should consult a qualified health care provider for professional medical advice, diagnosis and treatment of a medical or health condition.