Medicamentos biológicos para la artritis reumatoide

What are biological medicines?

Biological medicines are a group of newer medicines that are used to ease the symptoms of artritis reumatoide (AR) and reduce the damaging effect of the disease on the joints. Biological medicines mimic substances produced by the human body, such as antibodies. They are made by living organisms such as cloned human white blood cells. This is unlike most medicines which are made by chemical processes.

What else are biological medicines used to treat?

Biological medicines are also used to treat other conditions - for example, some other forms of artritis, and chronic inflammatory skin or bowel disease. However, the rest of this leaflet is only about biological medicines when they are used to treat rheumatoid arthritis.

There are quite a few biological medicines available to treat rheumatoid arthritis. They include adalimumab, certolizumab pegol, etanercept, golimumab, infliximab, anakinra, abatacept, rituximab, rituxan and tocilizumab. They come in various different brand names. Some biological medicines are sometimes called cytokine modulators or monoclonal antibodies.

There is another group of medicines called disease-modifying antirheumatic drugs (DMARDs) which can also be used to treat RA. Like biological medicines they have a disease-modifying effect against rheumatoid arthritis, which means that they treat the causes of RA and not just the symptoms. See the separate leaflet called Disease-modifying antirheumatic drugs (DMARDs) for more details.

Biological medicines work in rheumatoid arthritis by blocking chemicals in the body that are involved in inflammation.

For example, some of these biological medicines block a chemical called tumour necrosis factor alpha (TNF-alpha) which plays an important role in causing inflammation in the joints. Medicines that block TNF include adalimumab, certolizumab pegol, etanercept, golimumab, and infliximab. The other biological medicines (anakinra, abatacept, rituximab and tocilizumab) work in slightly different ways to each other, and to medicines that block TNF, but they all reduce inflammation.

Biological medicines are a type of targeted therapy, which means that they target one specific part of the malfunctioning immune system that is causing rheumatoid arthritis. Older treatments (like steroids) tend to affect the immune system more broadly, and suppress many aspects of the body's immune system.

Biological medicines are usually prescribed when you have taken at least two DMARDs for six months and your rheumatoid arthritis has not improved. They are only prescribed by doctors in a hospital who specialise in treating rheumatoid arthritis (rheumatologists).

If your doctor thinks that a biological medicine would work for you then you are usually asked to take a DMARD called methotrexate at the same time. Some people cannot take methotrexate and they may be asked to take a different DMARD.

In the NHS, biological medicines are offered based on criteria made by the National Institute for Health and Care Excellence (NICE). You can find out more about NICE's recommendations from the further reading list below.

Biological medicines used for RA include:

• Adalimumab.

• Certolizumab pegol.

• Etanercept.

• Golimumab.

• Infliximab.

• Abatacept.

• Sarilumab.

• Secukinimab.

• Tocilizumab.

• Rituximab.

There are also new biological medications being developed and released often.

Which one is used depends on several things, including what treatment you've had before. For example, some biological drugs are only used if another biological drug hasn't worked. Your specialists will tell you which drug they recommend.

Some biological medicines are also available as 'biosimilars'. Biosimilars are biological drugs that are very similar, but not completely identical to, an existing biological medicine. They have the same benefits and risks as the existing medicine. They are usually made by a different company once the patent on the existing biological medicine has expired.

Another type of drug, called a targeted synthetic DMARD, may also be offered as an alternative to biological medicines in some cases. Examples include apremilast, baricitinib, filgotinib, tofacitinib, or upadacitinib. These are different types of medicines to biological medicines, although they work in similar ways, in that they target part of the immune system.

Sometimes people have side-effects to these medicines in the first three months of treatment. If this happens, your doctor may try you on one of the other medicines that block TNF, or you may be given one of the other biological medicines that work in a slightly different way (usually rituximab). Your doctor will advise.

Biological medicines cannot be taken as a tablet or a liquid to swallow because they would be broken down in the gut and would not work. Some biological medicines are given by an injection under the skin - for example, etanercepto. You can either learn to inject yourself, or a nurse in the hospital will do it for you. Other biological medicines are given in the hospital by a drip into a vein in the arm. How often they are given depends on which one you are prescribed - it can vary from once a week to once every eight weeks.

It is thought that biological medicines work better than DMARDs at slowing joint damage. Unfortunately, they do not work for everyone and it is not possible before treatment starts to tell who will respond to them. If a biological medicine is going to work, you will probably feel better within 12 weeks.

Biological medicines are normally prescribed for six months. If your symptoms have not improved after six months then these medicines are usually stopped. Your doctor will discuss other treatments that you can try.

If biological medicines improve your rheumatoid arthritis, the specialist may consider keeping you on this medication in the long term. Once your rheumatoid arthritis is under control, the specialist may decide to try to reduce your dose and eventually stop your biological medicine. But the decision to continue or stop treatment will depend upon your symptoms and what the specialist feels is best for you.

It is not possible to list all of the adverse effects of each biological medicine in this leaflet. However, as with all medicines, there are a number of side-effects that have been reported with each of the biological medicines. If you want more information specific to your biological medicine then you should read the information leaflet that comes with your medicine.

Most biological medicines make you more prone to infections. These can be quite serious and some people have had severe infections such as infection of the blood (septicemia), as well as tuberculosis (TB) and hepatitis B reactivation. Blood tests and a chest X-ray are usually required before starting a biological medication - these include tests for hepatitis B, hepatitis C, and tuberculosis. If any of these are present, they can be treated - and it may be possible to use a biological medication later if treatment of the infection is successful.

Some biological medicines may also cause damage to the blood-producing cells.

You should tell your doctor or nurse straightaway if you develop any of the following after starting a biological medicine:

• Dolor de garganta.

• Una temperatura alta (fiebre).

• Any other symptoms of infection.

• Unexplained bruising.

• Sangrado.

These are all signs that you may be having side-effects to your medicine.

Other side-effects that have been reported include:

• Sentirse enfermo (nauseabundo).

• Dolor de barriga (abdominal).

• Dolor de cabeza.

• Depresión.

• Itching (pruritus).

• Injection site reactions.

Most hospitals will give you a biological therapy alert card to carry with you at all times. This is important because, if you become unwell, the doctor or nurse treating you needs to know you are being treated with a biological medicine, making you more at risk of infection.

These medicines sometimes react with other medicines that you may take. For example, people who are being treated with biological medicines cannot have certain types of vaccines called live vaccines. So, talk to your doctor and make sure they know of any other medicines that you are taking, including ones that you have bought rather than been prescribed. See the leaflet that comes with your particular brand for a full list of possible side-effects and cautions.

Most people will have a chest X-ray y análisis de sangre before starting a biological medicine. These tests are done to make sure you do not have TB and hepatitis B or C (as above) and that you do not have any problems with your blood-producing cells.

During treatment you will be monitored for any signs of TB, hepatitis B and other infections. You may also have further blood tests to see if your treatment is working.

You cannot buy biological medicines. They are only available with a doctor's prescription.

Biological medicines are usually avoided for people who:

• Have an active infection.

• Have certain other conditions, such as multiple sclerosis (some biological medicines may worsen these conditions).

• Have certain types of cancer.

• Have some types of heart problems, such as uncontrolled insuficiencia cardíaca.

There are also other situations where a doctor may feel that a biological medicine is too risky to use.

Some biological medicines can be used during pregnancy, and some should be stopped before or during pregnancy. Most biological medicines can be used whilst breastfeeding - the amount of medicine that enters breast milk is very small, and anything that does enter breast milk is likely to be broken down in your baby's stomach.

Always speak to your doctor if you are taking biological medicines if you are planning a pregnancy, are pregnant, or are breastfeeding.