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Immunosuppressants guide

Lesley Dobson / 13 October 2015

An introduction to immune-suppressing drugs, what they do and why we need them.

Man with a cold
Immune-suppressing drugs can cause an increased susceptibility to infection, so be careful around friends and family with colds and flu. Photo posed by model.

Immunosuppressants are vital for treating a range of medical conditions, including rheumatoid arthritis, ulcerative colitis, vasculitis, Crohn’s disease, and organ transplants. Here’s our guide to what they are, and why you might need them.

I’ve been prescribed immune-suppressing medication, how does it work?

“Treatment for many people with inflammatory arthritis, such as rheumatoid arthritis, psoriatic arthritis or Lupus (systemic lupus erythematosus -SLE), involves drugs that suppress the immune system,” explains Professor Philip Conaghan, University of Leeds & Arthritis Research UK advisor.

“The immune system is supposed to protect the body from injury, illness or disease, but when it goes wrong the immune system incorrectly detects a threat from the body’s own cells, which isn’t there.”

“In the case of rheumatoid arthritis for example, the immune system believes that there is a problem with cells in the joints and it then causes inflammation in those cells. Immunosuppressive drugs dampen down an overactive immune system to stop this happening,” says Professor Conaghan.

Nearly everyone who has an organ transplant must take immunosuppressant drugs. Without these, the patient’s body would see the transplanted heart, liver, or kidney for instance, as something foreign, and their immune system would attack it.

Immunosuppressant drugs prevent this happening, and give the transplanted body organ a much better chance of staying healthy.

Which other conditions are treated with immunosuppressants?

There are many different autoimmune diseases, at least 80 altogether. Over 40,000 people in the UK alone live with some form of inflammatory arthritis. These are just some of the other autoimmune conditions.

Are there different immunosuppressants?

There are many different immunosuppressants, used to treat the wide range of autoimmune conditions.

Commonly prescribed immunosuppressants include


Used to treat Crohn’s disease, rheumatoid arthritis, lupus (SLE), dermatomyositis, polymyositis and ulcerative colitis.


Used to treat lupus (SLE), vasculitis and myositis.


Used to treat eczema, (NHS UK)  psoriasis, rheumatoid arthritis, and to prevent organ transplants being rejected.


Used to treat lupus (SLE), rheumatoid arthritis, psoriatic arthritis, and vasculitis.

Mycophenolate mofetil

Used to treat lupus and to prevent organ transplants being rejected.


Used to treat ulcerative colitis and eczema, and to prevent organ transplants being rejected.

What side effects do immunosuppressants cause?

“There are a large number of immune-suppressing drugs, and there are specific side effects related to each,” explains Professor Conaghan.“

The most common side effects for methotrexate (prescribed for rheumatoid arthritis, psoriatic arthritis and vasculitis) are nausea, vomiting, diarrhoea, and mouth ulcers.

And for sulfasalizine, prescribed for rheumatoid arthritis, psoriatic arthritis and reactive arthritis, the most common side effects are nausea, diarrhoea, stomach pain, dizziness, headache and rashes.

If you are about to start taking immunosuppressants, or are taking them and are concerned about the side effects, talk to your consultant or GP. They might be able to suggest another drug, or ways of reducing the side effects.

Can suppressing your immune system cause problems?

“Most people on these drugs will not notice problems,” explains Professor Conaghan. “The main issue for most immune-suppressing drugs is that they can cause an increased susceptibility to infection. So be careful around friends and family with colds and flu, look after yourself if you do get any infections, and be careful to watch the healing of any wounds.”

“If people do pick up infections while on these drugs, there is a chance that it could be more serious. The effect of chicken pox, for instance, can be much more serious for people on immunosuppressive drugs.”

Among its other tasks, your immune system helps prevent you developing cancer. So taking immunosuppressants may increase your risk of developing cancer. If you are concerned about this risk, talk to your doctor.

Other side effects can include losing your appetite, vomiting and diarrhoea, bruising or bleeding, headaches, putting on weight, and liver damage.

How long will I need to stay on immunosuppressants?

This depends on your condition. If you have had an organ transplant you will probably have to always take immunosuppressants, to prevent your body rejecting your new heart or kidney.

If you have a very severe outbreak of hand eczema, for instance, you may be prescribed a short course of immunosuppressants, to help improve your condition.

“If an inflammatory arthritis goes into remission, after six months or a year, your doctor may consider reducing and then stopping your immune-suppressing drugs,” says Professor Conaghan.

“However, many people with inflammatory arthritis will need drugs for much of their life, because this condition can’t be cured. At best it can be brought under control.” Talk to your doctor to find out whether coming off these drugs is a possibility for you.

Do you have arthritis?

If you have arthritis and want to tell Arthritis Research UK how your condition affects you during National Arthritis Week, 12 – 18 October 2015, visit


The opinions expressed are those of the author and are not held by Saga unless specifically stated. The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.