RENAL TRANSPLANTS & FAILURE
The goals of pharmacotherapy are to prevent graft rejection, reduce morbidity, and prevent complications. Immunosuppression is often started prior to or during surgery.
Transplant recipients are maintained on an immunosuppression regimen that includes 1-3 drugs. Immunosuppressant drug classes include calcineurin inhibitors, corticosteroids, antimetabolites, mTor inhibitors, and other immunosuppressants. Several regimens can be used, including pretransplantation induction therapy and simple postoperative maintenance therapy; the choice of regimen depends on the training and experience of the transplantation center. For additional information, see the Medscape topic Immunosuppression.
What are immunosuppressants?
Immunosuppressants are drugs or medicines that lower the body’s ability to reject a transplanted organ. Another term for these drugs is anti-rejection drugs. There are 2 types of immunosuppressants:
1) Induction drugs: Powerful antirejection medicine used at the time of transplant
2) Maintenance drugs: Antirejection medications used for the long term.
Think of a real estate mortgage; the down payment is like the induction drug and the monthly payments are like maintenance drugs. If the down payment is good enough you can lower the monthly payments, the same as for immunosuppression.
There are usually 4 classes of maintenance drugs:
• Calcineurin Inhibitors: Tacrolimus and Cyclosporine
• Antiproliferative agents: Mycophenolate Mofetil, Mycophenolate Sodium and Azathioprine
• mTOR inhibitor: Sirolimus
• Steroids: Prednisone
• What are immunosuppressants used for?
When you get a kidney transplant, your body knows that the new kidney is foreign (that is, not originally part of your body). Your body will attack the new kidney and try to damage or destroy it. The immunosuppressant drugs suppress your body’s ability to do this. The goal is to adjust these drugs to prevent rejection and to minimize any side effects of the drugs.
Does everyone who gets a new kidney have to take immunosuppressants?
Almost everyone who has a transplant must take these drugs every day as directed. If your new kidney came from an identical twin, however, you may not have to take them. Even missing a single dose may make it more likely for you to have a rejection. The only time you should skip a dose is if your doctor or other health care team member tells you to do so. If you are not sure, call your doctor. Also, when you have a clinic visit, you should not take your immunosuppressant medicines until your blood is drawn for lab work.
Because of the large number of pills you may need to take each day, forgetting a dose is easy to do. You can do three things to help you remember your medicine:
1) Know the name of each drug you take and what it does. If you have a good understanding of your drugs, you will be less likely to forget one.
2) Use a pill box or organizer. This allows you to set up an entire week of pills. Once the week is set up, all you have to do 3) is take the pills in each on the right day and time.
Try to take your medicine at the same time every day.
What should I do if I miss a dose?
Take it as soon as you remember and call your doctor. If it is time for the next dose, do not take a double dose.
Are there any signs or symptoms I should watch for?
Yes. Even though you are taking your medicines every day, you may still develop rejection of the kidney transplant. You need to know your body very well. If you have any of the following, you should call your transplant center right away:
• a drop in your urine output
• a fever above 100 degrees
• tenderness of your new kidney
• bloody urine
• flu-like feelings
• weight gain (more than 3 pounds in two days)
The transplant center will probably ask you to have some blood tests and maybe other tests. The long-term success of your kidney transplant depends largely on careful follow-up and a good working relationship between you and your transplant team.
Are there any side effects from taking these drugs?
Yes. One of the side effects of these drugs is an increased chance of infections. This is more of a problem in the early period after a transplant or following treatment of a rejection because the dosage of these drugs is higher at these times. You should call the transplant center if you have:
• a fever above 100 degrees
• drainage from your surgical scar
• burning when you pass your urine
• a cold or cough that will not go away
The most common side effects of the immunosuppressant drugs are “stomach upset”. If this happens, ask your doctor if you can space your medicine at different times to help with this problem.
About 6 months to a year after transplant, the immunosuppression is usually lowered and the chance of side effects should be low. If you still have side effects, speak to your transplant team to either change the dose or switch to a different medicine. Changes to immunosuppressant medicine should only be made after checking with your transplant center.
Are there other medicines and food that can act against immunosuppressants?
Yes. There are many other medicines, food, and supplements that can change the levels (up or down) of immunosuppressants in the blood. Some of the common ones are grapefruit juice, St. John’s Wort, erythromycin, anti-TB (tuberculosis) medicines, anti-seizure medicines and common blood pressure medicines (cardizem or diltiazem, and Verapamil).