TNF inhibitors are medicines that help stop inflammation. They're used to treat diseases like rheumatoid arthritis (RA), juvenile arthritis, psoriatic arthritis, plaque psoriasis, ankylosing spondylitis, ulcerative colitis (UC), and Crohn's disease.
On this page you will find information about:
- Examples of TNF inhibitors
- What are TNF inhibitors?
- Subsidy restrictions
- How are TNF inhibitors given?
- Monitoring and investigations
- What are the side effects of tumour necrosis factor (TNF) inhibitors?
Examples of TNF inhibitors available in New Zealand include:
TNF inhibitors are used to treat certain types of autoimmune conditions. These are conditions in which your body's defence system (immune system) attacks healthy tissues. They include conditions such as:
- rheumatoid arthritis and psoriatic arthritis
- bowel conditions such as Crohn's disease, ulcerative colitis
- skin conditions such as chronic plaque psoriasis.
TNF inhibitors work by blocking natural inflammatory substances in your body called tumor necrosis factor alpha. This helps to decrease swelling (inflammation) and weakens your immune system, thereby slowing or stopping damage from the condition.
Watch videos about the use of adalimumab, etanercept and infliximab for the treatment of arthritis.
TNF inhibitors are expensive medicines with a potential for serious side effects. They are used in selected people when standard treatments have been unsuccessful. In New Zealand, TNF inhibitors are funded with restrictions (PHARMAC subsidy restrictions). To qualify for subsidy, the initial application for treatment must come from an appropriate named specialist, eg, a rheumatologist, gastroenterologist or dermatologist.
TNF inhibitors are given by injection.
- Adalimumab and etanercept are given by subcutaneous injection (into your skin), usually in your thigh or abdomen (tummy area). Change the site for each injection. Do not inject in an area that is bruised, red, hard or tender.
- Infliximab is given by intravenous infusion (as a drip) into a vein.
TNF inhibitors have the potential for serious side effects, including an increased risk of infection.
- Before prescribing a TNF inhibitor, your doctor will test for infections such as tuberculosis (TB), hepatitis and chickenpox.
- To monitor the safety of TNF inhibitors and how well they are working, your doctor will order blood tests before you start treatment and regularly while you are on it. Common tests used are full blood count, liver function test and C-reactive protein test.
Before starting on a TNF inhibitor, your doctor will review your immunisation record to make you have received all vaccinations recommended on the New Zealand Immunisation Schedule. You may need to catch-up if you have missed any vaccinations.
- Live vaccinations, such as varicella (chickenpox) vaccine, tuberculosis (BCG) and measles, mumps rubella (MMR), must be avoided if you are receiving treatment with a TNF inhibitor. They should be completed before starting treatment.
- The following vaccines are safe to take while receiving treatment with a TNF inhibitor:
Like all medicines, TNF inhibitors can cause side effects although not everyone gets them.
|Side effects||What should I do?|
|Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product|
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Useful resources for healthcare professionals
Cytokine modulators NZ Formulary
Humira Medsafe, NZ
Enbrel Medsafe, NZ
Remicade Medsafe, NZ
Stelara Medsafe, NZ
Biologic medicines for the treatment of inflammatory conditions – what does primary care need to know? BPAC, NZ, 2013