TNF Inhibitors

medicine injection

TNF inhibitors are a group of medications 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.

There are six different TNF inhibitors that have been approved by the U.S. Food and Drug Administration for the treatment of rheumatic diseases. To decrease side effects and costs, most patients with mild or moderate disease may be 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.

How to Take It

The starting doses for RA are shown in Table 1. Doses may vary for other rheumatic conditions. 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 through the vein and are given at a doctor’s office or an infusion center. These infusions can take up to four 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 two or three doses, but it usually takes three months to see the full benefit.

TABLE 1: Comparison of TNF inhibitors in RA
Drug Usual Dosing Regimen
Infliximab (Remicade)

Initially: Given at the clinic or at an infusion center as an intravenous infusion (IV) at a dose of 3-5 mg/kg (according to body weight) at weeks 0, 2, and 6.

Maintenance: IV infusions every 8 weeks. Dose may be increased to 5-10 mg/kg and frequency may be increased to every 4 weeks.

Etanercept (Enbrel)

Initially: 50 mg once a week or 25 mg twice a week as a self-administered subcutaneous injection. Higher doses may be used short term in some conditions.

Maintenance: Same

Adalimumab (Humira)

Initially: 40 mg every other week as a self-administered subcutaneous injection. Higher doses may be used short term in some conditions.

Maintenance: Same

Golimumab (Simponi)

Initially: 50 mg once per month as a self-administered subcutaneous injection.

Maintenance: Same

Golimumab (Simponi Aria)

Initially: Given at the clinic or at an infusion center as an IV at a dose of 2 mg/kg (according to body weight) at weeks 0 and 4.

Maintenance: IV infusions every 8 weeks.

Certolizumab pegol (Cimzia) 

Initially: 400 mg (given as 2 x 200 mg injections) self-administered every 2 weeks at weeks 0, 2 and 4. It can also be mixed and administered in your doctor’s office.

Maintenance: 200 mg every 2 weeks or 400 mg (2 x200 mg injections) every 4 weeks as a self-administered injection. It also can be mixed and administered in your doctor’s office.

Side Effects

The most common side effect seen with the injectable drugs are skin reactions, commonly referred to as “injection site reactions.” The patients usually complain of a localized rash with burning or itching. These reactions can last up to a week. Infliximab has been associated with a severe allergic reaction with swelling of the lips, difficulty breathing and low blood pressure. Your doctor will usually order a pre-medication to decrease the chances of an infusion reaction.

The most significant side effect 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 such an infection can worsen during treatment. The usual way of testing is with a skin test, but a blood test is also available.

Long-term use of TNF inhibitors may increase the risk of cancers such as lymphoma and skin cancer. There are rare neurologic complications as well.. People who have a history of multiple sclerosis should not use them. People with significant heart failure should not use a TNF inhibitor, because their heart disease could worsen.

Tell Your Doctor

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 doctor 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 doctor 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 March 2019 by Ali Duarte, MD, 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.

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