TNF Inhibitors: What You Need to Know

FAQs About These Rheumatoid Arthritis Drugs

TNF inhibitors are medications for treating rheumatoid arthritis. As with any drug, they can be very effective for some people and less so for others. Here's a look at what TNF inhibitors are and how they work, what their potential side effects are, and how specific ones compare.

What Are TNF inhibitors?

TNF inhibitors are sophisticated, complicated drugs that belong in a class of medications called biologics. They work by targeting a substance called tumor necrosis factor that causes inflammation. Some biologics for treating rheumatoid arthritis are monoclonal antibodies.

Biologics are drugs that target molecules that cause inflammation and damage joints. They're often prescribed for people who are taking other types of arthritis medications, such as DMARDs (disease modifying anti-rheumatic drugs), but not getting enough relief.

Tumor Necrosis Factor is a protein produced by the immune system. It plays a role in a number of vital physical functions, such as fat metabolism and the coagulation, or clotting, of blood cells. Certain conditions, including cancer and autoimmune diseases like rheumatoid arthritis, can cause the overproduction of TNF, which in turn leads to inflammation.

You already know that antibodies are substances produced by the immune system to fight off antigens such as viruses. Monoclonal antibodies are produced in the lab and designed to target specific molecules, such as TNF.

Comparing TNF Inhibitors

It's always important to look at the similarities and differences between medications when you and your doctor are homing in on a treatment that's just right for you. Some factors to consider when choosing among TNF blockers are how each is given, side effects, and cost.

Enbrel (etanercept) was the first anti-TNF drug. It was approved by the U.S. Food and Drug Administration (FDA) in 1998. Enbrel is derived by introducing human DNA into Chinese hamster ovary cells to create genetically engineered proteins. 

Remicade (infliximab) is a monoclonal antibody that binds to and blocks tumor necrosis factor alpha (TNF-alpha). It was the second TNF inhibitor to be FDA-approved, in 1999.

Humira (adalimumab) is a "fully humanized" monoclonal antibody, meaning the actual makeup of the drug is identical to that of human antibodies, even though it was created in a lab. Humira was approved by the FDA in 2002.

Cimzia (certolizumab pegol) is the only TNF inhibitor that touts being less poisonous to cells because of its chemical properties. In addition, compared to other anti-TNF drugs, Cimzia reportedly has a higher affinity for human TNF.


Simponi (golimumab) is a TNF-alpha blocker that's also prescribed for ulcerative colitis, psoriatic arthritis, and ankylosing spondylitis. It was approved in 2004.

Side Effects of TNF Blockers

No medication is without side effects. Certain potential problems linked to TNF blockers are well known, causing some arthritis patients to be wary of taking TNF inhibitors. But for most folks, the benefits far outweigh the risks.

Some patients are prone to infection while being treated with DMARDs or biologic drugs. (The same is true of DMARDs.)

A 2016 study found that people who took certain TNF blockers for rheumatoid arthritis had three times the risk of developing certain cancers, such as lymphoma. This was especially true if they were on high doses.

Read All About It

Arthritis Without Pain - The Miracle of TNF Blockers

This book by rheumatologist Scott J. Zashin, MD, explains how TNF blockers work and how they compare to other arthritis drugs. He includes patient success stories and goes into how this breakthrough class of drugs has changed lives.

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