Immunosuppressive drugs (also called anti-rejection drugs) are important because they prevent the body rejecting a transplanted kidney. Rejection occurs when the body recognises the new kidney as ‘foreign’ and switches on the immune system of the body setting off a chain of events that can damage the kidney. This damage can occur rapidly, known as acute rejection, or it can occur over a long period of time, known as chronic rejection. Rejection may happen despite close matching of the donated kidney and the transplant patient.
Immunosuppressive drugs greatly reduce the risks of rejection, protecting the kidney and preserving its function. These drugs aim to block the immune system so that it is less likely to react against the transplanted kidney. A variety of drugs achieve this same basic aim but work in different ways to reduce the reaction.
Five drugs are currently used in kidney transplantation for immunosuppression. They can be separated into three groups:
1 Cyclosporin (brand names Neoral & Sandimmun) Tacrolimus (brand name Prograf)
2 Azathioprine (many brands available) Mycophenolate mofetil (brand name Cellcept)
3 Prednisolone (many brands available)
Most people start on a combination of drugs after their transplant, one from each of the above groups e.g. cyclosporin, azathioprine and prednisolone. Over a period of time the doses of each drug and the number of drugs taken may be reduced as the risks of rejection decline. However, most people need to take at least one immunosuppressive for the rest of their lives.
To get the maximum benefit from the drugs, it is vital that they are taken regularly.
Anti-rejection drug regimes need to be closely monitored. For example, blood levels of cyclosporin or tacrolimus are checked regularly. If the levels of a drug in the blood are too low the doctor may increase the dose of the drug to ensure that the kidney is protected from rejection. If the levels are too high your doctor may decrease the dose of the drug because of side effects. Kidney function, white blood cell count and adverse reactions to drugs will also be frequently checked.
Some drugs may have an adverse effect on immunosuppressive therapy. This is particularly important for people taking cyclosporin or tacrolimus. Some drugs can cause the blood levels of the immunosuppressives to rise, while others can cause the blood levels to fall. Before taking any new drugs, even ones bought over the counter from the chemist, please check with a doctor or pharmacist first.
For information on the side effects of specific drugs please refer to the manufacturer’s ‘patient information leaflet’ which will be found in the drug packaging or to the drug information cards available in this library in the drugs section. Alternatively, speak to your doctor or pharmacist for advice.
increased risk of infection – is a common side effect of all the immunosuppressives. The body’s immune system protects us from infections and when the immune system is suppressed we are more likely to pick up infections. Taking antibiotics such as co-trimoxazole prevents some of these infections. It is very important to report the signs of infection, such as fever, to your doctor so that the appropriate treatment can be started as quickly as possible.
slightly increased risk of cancer - the immune system also plays a role in protecting the body against some forms of cancer. With long term use of immunosuppressive drugs there is, by comparison with the general population, an increased risk of developing skin cancer -caused by a combination of the drugs and exposure to sunlight (see the leaflet on skin care after transplant) – non-Hodgkin’s lymphoma and carcinoma of the cervix, however, these diseases are uncommon.