Infliximab is a biologic medication that is used to treat severe psoriasis and/or psoriatic arthritis. It is known by the brand names Remicade, Flixabi, Remsima, Zessly and Inflectra.

What is Infliximab?

Remicade was the first version of Infliximab to be made and is the ‘originator’ medicine. The patent for Remicade expired in 2018, at which point the four Infliximab biosimilars; Flixabi, Remsima, Zessly and Inflectra came to the market. The Infliximab biosimilars work in the same way as the originator and have the same treatment effects, but there are slight differences between them i.e. they are ‘similar’ to the original biologic medicine. You should be prescribed Infliximab by the brand name (Remicade, Flixabi, Remsima, Zessly or Inflectra) so that it is clear which is being used.

Biologics are modern medications that are made using living cells, designed to change or mimic processes within the human body.

All versions of Infliximab are taken by infusion.

You can read more about who Infliximab is suitable for in the ‘Who is it for?’ section on this page.

How does Infliximab work?

Infliximab blocks tumour necrosis factor-alpha (TNF alpha) a chemical ‘messenger’ in the immune system that signals other cells to cause inflammation. There is too much TNF alpha in the skin of people with psoriasis and the joints of people with psoriatic arthritis, which causes inflammation and can lead to tissue and joint damage. TNF alpha can also lead to increased activity of the immune system by switching on certain white blood cells in the body, called T cells. Once T cells become overactive they can trigger inflammation and other immune responses, encouraging the development of psoriasis or pain and joint damage in psoriatic arthritis.

Infliximab helps lower the amount of TNF alpha to more normal levels, and switches off the inflammatory cycle of psoriasis and psoriatic arthritis. This leads to improvement in symptoms for many people who take it.

Who is Infliximab for?

Infliximab can be prescribed to treat very severe plaque psoriasis in adults. Usually it will only be offered to people after other biologics have failed or who have not responded to, or cannot take non-biologic systemic treatments including ciclosporin, methotrexate or PUVA light therapy.

Infliximab can also be prescribed to treat active and ‘progressive’ (worsening) psoriatic arthritis in adults, if the response to other disease modifying anti-rheumatic drug treatments has been inadequate. This means that if you have taken treatments such as methotrexate, sulfasalazine or leflunomide for your psoriatic arthritis without a good response, you could be offered Infliximab.

Who should not take Infliximab?

  • People with active infections should not start Infliximab. You will be tested to check for infections, for example tuberculosis (TB) and hepatitis, before starting treatment.
  • In most cases, pregnant women should not be treated with Infliximab and women should not breastfeed during treatment with Infliximab. Women should not fall pregnant or breast feed for six months after treatment has stopped.
  • Infliximab should be used with caution in people with multiple sclerosis or other similar types of demyelinating (destruction of nerve tissue) neurological diseases. Your Dermatologist or Rheumatologist should discuss this with you, if relevant.
  • Infliximab should also be used with caution in elderly people, those with already impaired immune systems, or a history of heart failure or cancer. Again, your Dermatologist or Rheumatologist will discuss this with you, if relevant.
  • You should tell your doctor if you have had treatment with Infliximab in the past and are now starting Infliximab treatment again. If you have had a break of more than 16 weeks, there is a higher risk of allergic reactions when you start the treatment again.

How is Infliximab used?

The usual dose of Infliximab is 5 mg for every kg of body weight. Infliximab comes as a powder that has to be mixed with sterile water and given into a vein by a healthcare professional. This method of administration is known as an ‘infusion’.

It takes around two hours to receive the full dose of Infliximab, and you will usually be asked to wait for a while after the infusion to make sure you do not develop an allergic reaction. An infusion will be given at the start of the course of treatment, and again after two and six weeks. After that, they are usually given every six to eight weeks.

Infliximab can be prescribed by itself or is sometimes used in combination with methotrexate. Due to the higher costs associated with Infliximab, and the inconvenience to the patient, Infliximab is often not a first choice biologic to treat severe psoriasis. The British Association of Dermatologists recommends it is used only for the most severe psoriasis, when other biologics have failed or cannot be used or where weight-based dosing is a priority.

People taking Infliximab will have regular blood tests every three to six months- usually carried out by Dermatology Nurses, or by their own GP- to monitor for infections or other possible effects of the treatment. People taking Infliximab should have an annual flu jab, but should check with a doctor or nurse before having any other vaccinations or taking other medication.

Live vaccines such as yellow fever, shingles and rubella aren’t recommended for people currently being treated with Infliximab. Biologic therapy should be stopped for 6-12 months before receiving a live vaccine.

What are the unwanted side effects?

As with all medications, some side effects are possible when taking Infliximab. It is important to remember that not every person taking a medication will get all, or even any, of the possible side effects listed. Many side effects of Infliximab are mild and do not cause most patients to stop taking it.

Infliximab can cause serious allergic reactions during the infusion, and for up to two hours afterwards. For this reason a doctor or nurse will monitor you during this period. You may also be given other medications to treat or prevent reactions to Infliximab.

The most common side effects for people taking Infliximab include viral infections, upper respiratory infections (such as sinusitis), headache, stomach pain, nausea, fever, cough, red or hot skin, dental problems and pain around the infusion site.

Because Infliximab works by suppressing part of the activity in the immune system, it can make people taking it more prone to serious infections than they usually would be. If you are over 65, then you may have a greater risk.

Tell your doctor before you are given Infliximab if you have an infection even if it is a very minor one or if you develop any signs of infection during treatment. Signs include fever, cough, flu-like signs, feeling unwell, red or hot skin, wounds or dental problems. If a serious infection occurs your doctor will most likely stop Infliximab.

Although side effects are possible with this, and any, treatment, it is important to remember that people taking Infliximab have regular blood tests to check for health issues. If you are worried about the side effects of Infliximab, you should discuss these with your doctor.

How long will Infliximab take to work?

It can take a number of weeks before a person’s psoriasis or psoriatic arthritis improves on Infliximab. If considerable improvement is not seen in ten weeks, treatment with Infliximab will be stopped. If this happens, a Dermatologist or Rheumatologist should discuss the next available options with you - there are a number of other biologic or systemic treatments that can be tried if Infliximab does not work.

How safe and effective is Infliximab?

Infliximab has been used to treat psoriasis in the UK since 2008 and psoriatic arthritis in the UK since 2006. The British Association of Dermatologists conducted a network meta-analysis, a type of study which puts together data from many trials of medications for psoriasis and found that infliximab was one of the best biologic treatments for clearing psoriasis. However, it was also one of the biologic treatments that had more people withdraw from the trials because they had an unwanted effect.

‘Real-world’ safety and effectiveness data is being compiled by the British Association of Dermatologists Biologics Interventions Register (BADBIR). Data from BADBIR showed that people with psoriasis receiving infliximab had a twofold increase in the risk of being admitted to hospital for an infection compared with those receiving standard tablet treatments. It is recommended that all people taking biologic treatments for their psoriasis should be asked for their data to be included in this register.

You should inform your doctor or nurse straight away if you notice any signs of an infection as infliximab may need to be stopped.

The information on this page is not intended to replace that of a healthcare professional: If you have any concerns or questions about your treatment, do discuss this with your doctor and always read the patient information leaflet to make sure you are using them correctly.


The information on this page is also available in our Infliximab information sheet.

March 2021 (Review Date: March 2024)