Rheumatology
Calcineurin inhibitors
Ciclosporin and tacrolimus — Powerful immunosuppressants that prevent transplant rejection and treat severe immune conditions — closely monitored.
Education and reference only. This is a plain-language class overview — it deliberately contains no doses. Always check the current Summary of Product Characteristics (SmPC), the BNF and your local formulary before prescribing or administering any medicine.
Quick answer
What is Calcineurin inhibitors?
Calcineurin inhibitors are strong immunosuppressant medicines used to stop the body rejecting a transplanted organ and to treat severe immune-driven conditions. Tacrolimus is also used as a cream/ointment for eczema.
- How it works: They block calcineurin, a switch the immune system's T-cells need to activate and multiply, so the immune attack on a transplant or in an autoimmune disease is suppressed.
- In practice: In practice calcineurin inhibitors (ciclosporin and tacrolimus) are cornerstone immunosuppressants after organ transplantation and are also used in severe eczema, psoriasis and some other immune diseases, with topical tacrolimus widely used for eczema.
What it is
Calcineurin inhibitors are strong immunosuppressant medicines used to stop the body rejecting a transplanted organ and to treat severe immune-driven conditions. Tacrolimus is also used as a cream/ointment for eczema. They are powerful and need careful monitoring.
How it works
They block calcineurin, a switch the immune system's T-cells need to activate and multiply, so the immune attack on a transplant or in an autoimmune disease is suppressed. Dialling the immune response down this powerfully is what both prevents rejection and explains the infection, kidney and other risks that require monitoring.
In practice
In practice calcineurin inhibitors (ciclosporin and tacrolimus) are cornerstone immunosuppressants after organ transplantation and are also used in severe eczema, psoriasis and some other immune diseases, with topical tacrolimus widely used for eczema. The dominant practical themes are narrow margins, monitoring and interactions. Blood levels are measured and dosing kept within a tight target, because too little risks rejection or flare and too much risks toxicity — chiefly to the kidneys, plus high blood pressure, tremor, and (differing between the two) effects such as raised blood sugar and diabetes, gum overgrowth and extra hair with ciclosporin, or neurological effects with tacrolimus. They interact with a long list of drugs (and with grapefruit) that raise or lower their levels, so nothing is added without checking. As broad immunosuppressants they raise infection and skin-cancer risk, so sun protection and infection vigilance matter, and live vaccines are avoided. Brand and formulation are kept consistent because switching can change levels. The same drug given topically for eczema acts locally with minimal absorption and avoids the skin-thinning of steroids.
Examples
Practical use
How to take it & use it well
- Take it at the same times each day exactly as prescribed, as a steady level is essential to protect a transplanted organ or control your condition.
- Stay on the same brand and form unless your specialist arranges a change, since different versions are not always interchangeable and swapping can alter your level.
- Avoid grapefruit and grapefruit juice, which can raise the level in your blood and increase the risk of side effects.
- For topical tacrolimus used on the skin, apply a thin layer to the affected area, wash your hands afterwards, and use sun protection, as it is meant to spare you from long-term steroid creams.
- Keep all your blood tests, which check the drug level along with your kidneys, blood pressure and salts, and report tremor, headaches or swelling.
- Protect yourself from infection and skin cancer by practising good hygiene, using sun cream and avoiding live vaccines unless your specialist agrees.
Common uses
- Preventing organ-transplant rejection
- Severe eczema, psoriasis and some autoimmune diseases
- Topical tacrolimus for eczema (steroid-sparing)
Monitoring
- Drug blood levels and kidney function
- Blood pressure, blood sugar and signs of toxicity
- Infection and skin-cancer surveillance; consistent brand/formulation
Weighing it up
Advantages & disadvantages
Advantages
- They are a cornerstone of preventing rejection after organ transplant, helping the new organ survive.
- They strongly suppress an overactive immune system, which also helps in some severe immune conditions.
- Blood levels can be measured, allowing treatment to be tuned to the right amount for each person.
- Topical tacrolimus treats eczema in delicate areas without the skin-thinning that long-term steroid creams can cause.
- There is long experience with these medicines, so their effects and monitoring are well understood.
Disadvantages
- They can harm the kidneys over time, which is one reason regular blood tests are needed.
- They commonly raise blood pressure and can cause tremor, headaches and changes in salts.
- By suppressing immunity, they raise the risk of infections and certain cancers, including skin cancer.
- They interact with many medicines and with grapefruit, so the level can swing up or down easily.
- Live vaccines are generally avoided while taking them, as they may not be safe.
Key safety principles
What to watch for
- Narrow margin — blood levels are measured and kept in a tight target; main toxicity is to the kidneys, plus raised blood pressure and tremor.
- Many interactions (and grapefruit) raise or lower levels — never add medicines without checking; keep the same brand/formulation.
- Broad immunosuppression raises infection and skin-cancer risk — sun protection, infection vigilance, and avoid live vaccines.
Key interactions
What to avoid or check alongside
- Grapefruit juice and many medicines, including some antibiotics and antifungals, raise the level and the risk of side effects.
- Other drugs, including some used for epilepsy and the herbal product St John's wort, lower the level and risk under-treatment or rejection.
- Combining them with other medicines that can harm the kidneys adds to the strain on the kidneys.
- Live vaccines are usually avoided, as a suppressed immune system can make them unsafe.
- Tell every prescriber and pharmacist that you take one of these, as even short courses of other medicines can disturb the level.
Patient & carer advice
- Attend your blood tests and take it at the same times — the level needs to stay just right
- Avoid grapefruit and check before adding any new medicine, including over-the-counter ones
- Protect your skin from the sun and tell us early about any infection
Use with
Related clinical calculators
Dose and risk decisions for this class often depend on renal function, weight or bleeding/stroke risk. These tools help:
Answers
Calcineurin inhibitors: frequently asked questions
Why do I need regular blood tests on these medicines?
The blood tests do two jobs: they measure the level of the medicine, which needs to stay in a careful range, and they check your kidneys, blood pressure and salts, which these drugs can affect. Keeping the appointments protects both your organ and your general health.
Can I eat grapefruit while taking ciclosporin or tacrolimus?
No, it is best avoided. Grapefruit and its juice raise the level of these medicines in your blood, which increases the risk of side effects and kidney strain. Choose other fruits and juices while you are taking them.
Why does it matter if my brand changes?
Different brands and forms of these medicines are not always exactly interchangeable, so a switch can change your level and risk either side effects or rejection. Stay on the same brand where possible, and if your supply changes, tell your team so your level can be checked.
Is tacrolimus cream safe to use long term on eczema?
Topical tacrolimus is designed to treat eczema, including in delicate areas like the face, without the skin-thinning that long-term steroid creams can cause. Use a thin layer as directed and protect treated skin from strong sun. Your prescriber will advise how long to use it.
Can I have my usual vaccines while on these medicines?
Live vaccines are generally avoided because your immune system is suppressed and they may not be safe. Many non-live vaccines are still recommended, though they may work a little less well. Always check with your specialist before any vaccine.
Authoritative sources
Always verify against the source
This overview is for orientation. For doses, interactions, contra-indications and the full monograph, use:
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