Infliximab

Generic name: infliximab [ in-FLIX-ih-mab ]
Brand names: Avsola, Inflectra, Remicade, Renflexis
Dosage form: intravenous powder for injection (100 mg)
Drug classes: Antirheumatics, TNF alfa inhibitors

Medically reviewed by Carmen Pope, BPharm. Last updated on Jun 25, 2023.

What is infliximab?

Infliximab is a type of biological therapy called a monoclonal antibody that may be used to treat certain autoimmune conditions characterized by inflammation such as:

Rheumatoid arthritis in adults which is also being treated with methotrexate
Ankylosing spondylitis in adults
Psoriatic arthritis in adults
Chronic, severe, plaque psoriasis in adults when other treatments are less appropriate
Crohn's disease in adults and children 6 years of age and older that has not improved with other medications or adults with fistulizing disease
Ulcerative colitis in adults and children 6 years of age or older that has not improved with other medications.

Instead of having generics, infliximab has biosimilars. Biosimilars are near-identical copies of the first brand of infliximab (Remicade) and just as safe and effective with similar dosing regimens. Although there are no clinically meaningful differences, they are usually significantly less expensive. There are four FDA-approved biosimilars of infliximab but only three are available on the U.S. market:

infliximab-axxq (Avsola)
infliximab-dyyb (Inflectra)
infliximab-abda (Renflexis).

How does infliximab work?

Infliximab works by binding specifically to a protein called TNF-α (tumor necrosis factor-alpha), which is released by white blood cells as part of our body’s immune response to infection or invasion by foreign substances. Overproduction of TNF-α can cause inflammation, which can damage tissues, bones, and cartilage, and also cell death. When infliximab binds to TNF-α, it blocks its effects, and this reduces inflammation. Increased levels of TNF-alfa have been found in conditions such as rheumatoid arthritis, psoriasis, and ankylosing spondylitis.

Infliximab is called a monoclonal antibody because the definition of monoclonal antibodies is that they bind specifically to a protein – in this case, infliximab binds specifically to TNF-α. Infliximab belongs to the class of medicines known as TNF alfa inhibitors or TNF blockers.

Warnings

Serious hypersensitivity or infusion reactions including anaphylaxis have occurred with infliximab. Infliximab should not be given to people with previous hypersensitivity reactions to infliximab or any inactive ingredients of Infliximab or to any murine proteins.

Dosages of infliximab greater than 5 mg/kg should not be given to patients with moderate or severe heart failure.

Infection risk

Infliximab affects your immune system and can reduce its ability to fight infections. Serious infections have happened in patients receiving infliximab, such as tuberculosis (TB) and infections caused by viruses, fungi, or bacteria. Some patients have died from these infections.

Before you start using infliximab, your doctor may perform tests to make sure you do not have certain infections, and your doctor should monitor you closely for signs and symptoms of an infection including TB during treatment.

Before starting infliximab, tell your doctor if you:

are being treated for an infection, have TB or hepatitis B, or have been in close contact with someone with TB or hepatitis B
have signs of an infection, such as a fever, cough, flu-like symptoms
have any open cuts or sores on your body
have diabetes or an immune system problem. People with these conditions have a higher chance of infections
live or have lived in certain parts of the country (such as the Ohio and Mississippi River valleys) where there is an increased risk of getting certain kinds of fungal infections (histoplasmosis, coccidioidomycosis, or blastomycosis). These infections may develop or become more severe if you receive infliximab. If you do not know if you have lived in an area where histoplasmosis, coccidioidomycosis, or blastomycosis is common, ask your doctor
use or have used other biologics such as anakinra, abatacept, or tocilizumab to treat the same condition.

Call your doctor if you have a fever, tiredness, flu symptoms, cough, or skin sores.

Risk of Cancer

Using infliximab may increase your risk of developing certain types of cancer, including a rare fast-growing type of lymphoma (called hepatosplenic T-cell lymphoma) that can be fatal.

Skin cancers are also more common in people being treated with infliximab. Call your doctor if you notice any changes in the appearance of your skin.

Other people at higher risk of developing cancer with infliximab include:

People with Chronic Obstructive Pulmonary Disease (COPD)
Women over the age of 60 being treated for rheumatoid arthritis (cervical cancer).

Liver toxicity

Serious liver toxicity has been reported with infliximab, some cases required liver transplantation or were fatal. Tell your doctor if you notice any abdominal pain or yellowing of your skin or eyes.

Before taking this medicine

You should not be treated with infliximab if you are allergic to it or any components of the injection.

Tell your doctor if you have ever had tuberculosis (TB) or if anyone in your household has tuberculosis. Also, tell your doctor if you have recently traveled. Tuberculosis and some fungal infections are more common in certain parts of the world, and you may have been exposed during travel.

Tell your doctor if you have ever had:

an active infection (fever, cough, flu symptoms, open sores, or skin wounds)
cancer
chronic obstructive pulmonary disease (COPD)
diabetes
heart failure or other heart problems
a weak immune system
liver failure, hepatitis B, or other liver problems
a nerve-muscle disorder, such as multiple sclerosis or Guillain-Barré syndrome
numbness or tingling anywhere in your body
phototherapy for psoriasis
seizures
vaccination with BCG (Bacille Calmette-Guérin) or if you are scheduled to receive any vaccines.

Make sure your child has received all their routine childhood vaccinations before starting infliximab. Infliximab is not for use in children younger than 6 years old.

If you use infliximab while you are pregnant, make sure any doctor caring for your new baby knows that you used the medicine during pregnancy. Being exposed to infliximab in the womb could affect your baby's vaccination schedule during the first 6 months of life.

You should not breastfeed while you are receiving infliximab.

How is infliximab administered?

Infliximab is given as a slow infusion into a vein. A healthcare provider will give you this injection and it will take at least 2 hours to complete.

The dosage of infliximab and how often it is given may vary depending on the condition being treated.

You may be watched closely after receiving infliximab, to make sure the medicine has not caused any serious side effects and your doctor will need to examine you regularly, to make sure you do not develop an infection or other side effects from infliximab.

If you need surgery, tell the surgeon ahead of time that you are using infliximab.

What happens if I miss a dose?

Call your doctor for instructions if you miss an appointment for your infliximab injection.

What happens if I overdose?

An overdose is unlikely as infliximab is given by a healthcare provider.

What should I avoid while receiving infliximab?

Avoid activities that may increase your risk of bleeding injury.

Do not receive a "live" vaccine while using infliximab, or you could develop a serious infection. Live vaccines include measles, mumps, rubella (MMR), polio, rotavirus, typhoid, yellow fever, varicella (chickenpox), and zoster (shingles).

What are the side effects of infliximab?

Get emergency medical help if you have signs of an allergic reaction: hives; chest pain, difficulty breathing; fever, chills, severe dizziness; swelling of your face, lips, tongue, or throat.

Some side effects may occur during the injection. Tell your caregiver if you feel dizzy, nauseated, light-headed, itchy, tingly, short of breath, or have a headache, fever, chills, muscle or joint pain, pain or tightness in your throat, chest pain, or trouble swallowing during the injection. Infusion reactions may also occur within 1 or 2 hours after injection.

Serious and sometimes fatal infections may occur during treatment with infliximab. Call your doctor right away if you have signs of infection such as fever, extreme tiredness, flu symptoms, cough, or skin symptoms (pain, warmth, or redness).

Also, call your doctor if you have:

skin changes, new growths on your skin
easy bruising or bleeding
a delayed allergic reaction (up to 12 days after receiving infliximab), symptoms may include a fever, sore throat, trouble swallowing, headache, joint or muscle pain, skin rash, or swelling in your face or hands
liver problems--right-sided upper stomach pain, loss of appetite, yellowing of your skin or eyes, and not feeling well
lupus-like syndrome--joint pain or swelling, chest discomfort, feeling short of breath, skin rash on your cheeks or arms (worsens in sunlight)
nerve problems--numbness or tingling, problems with vision, weakness in your arms or legs, or a seizure
new or worsening psoriasis--skin redness or scaly patches, raised bumps filled with pus
signs of heart failure--shortness of breath with swelling of your ankles or feet, rapid weight gain
signs of a stroke--sudden numbness or weakness, trouble speaking or understanding what is said to you, problems with vision or balance, severe headache
signs of lymphoma--fever, night sweats, weight loss, stomach pain or swelling, chest pain, cough, trouble breathing, swollen glands (in your neck, armpits, or groin) or
signs of tuberculosis--fever, cough, night sweats, loss of appetite, weight loss, feeling constantly tired.

Serious infections may be more likely in adults who are 65 years or older.

The most common side effects reported with infliximab include:

Upper respiratory tract infections
Nausea
Headache
Sinusitis
Diarrhea
Abdominal pain
Sore throat
Coughing
Bronchitis
Rash
Dyspepsia
Tiredness
Urinary tract infection
Pain or joint pain
Itch
Fever
High blood pressure
Yeast infection.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect infliximab?

Some medications may affect how infliximab works or increase the risk of side effects. Tell your doctor about all your other medicines, especially:

abatacept
anakinra
tocilizumab
any "biologic" medications you take such as adalimumab, certolizumab, etanercept, golimumab, natalizumab, rituximab, and others; or
any other medicines to treat Crohn's disease, ulcerative colitis, rheumatoid arthritis, ankylosing spondylitis, psoriatic arthritis, or psoriasis.

This list is not complete. Other drugs may affect infliximab, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Ingredients

Active: Infliximab 100mg, a chimeric IgG1κ monoclonal antibody (composed of human constant and murine variable regions). Produced by a recombinant murine myeloma cell line, SP2/0.

Inactive: dibasic sodium phosphate, dihydrate (6.1 mg), monobasic sodium phosphate, monohydrate (2.2 mg), polysorbate 80 (0.5 mg), and sucrose (500 mg).

Storage

Unopened infliximab vials should be stored in a refrigerator at 2°C to 8°C (36°F to 46°F).

If needed, unopened infliximab vials may be stored at room temperatures up to a maximum of 30°C (86°F) for a single period of up to 6 months but not exceeding the original expiration date. The new expiration date must be written in the space provided on the carton. Once removed from the refrigerator, infliximab cannot be returned to the refrigerator.

Once reconstituted, the infliximab infusion should begin within 3 hours of reconstitution and dilution.

Popular FAQ

What is the mechanism of action of infliximab?

Infliximab works by binding specifically to a protein called TNF-α (tumor necrosis factor-alpha), which is released by white blood cells as part of our body’s immune response to infection or foreign substances. Overproduction of TNF-α can cause inflammation which can damage tissues, bones, and cartilage, and also cell death. When infliximab binds to TNF-α, it blocks its effects, and this reduces inflammation. Increased levels of TNF-alfa have been found in conditions such as rheumatoid arthritis, psoriasis, and ankylosing spondylitis. Continue reading

What is the difference between Inflectra and Remicade?

Inflectra (infliximab-dyyb) is a biosimilar to Remicade (infliximab). They belong to the same class of drugs called tumor necrosis factor (TNF) alfa inhibitors. Inflectra can be prescribed for the same uses as Remicade, including rheumatoid arthritis, Crohn’s disease, ankylosing spondylitis, ulcerative colitis, psoriatic arthritis, and plaque psoriasis. Continue reading

What is the difference between Renflexis and Remicade?

Renflexis (infliximab-abda) is a tumor necrosis factor (TNF) blocker that is biosimilar to Remicade (infliximab). A biosimilar has no clinically meaningful differences in terms of safety and effectiveness from the reference product.

Renflexis is given as an intravenous (IV) infusion similar to Remicade, and is used for the same conditions, including rheumatoid arthritis, Crohn's disease and psoriatic arthritis. Biosimilars may lead to cost-savings due to a lower price and are preferred by some insurance companies. Continue reading