The new kidney is not the patient’s own organ, so the immune system will inevitably attack this “foreign body”, i.e. “rejection reaction”, so that the new kidney is continuously damaged, and eventually lead to impaired function. Therefore, patients need to protect the new kidney with reasonable immunosuppressive drugs. As the name implies, the function of immunosuppression is to “suppress the immune response”, so that the immune system and the new kidney can “coexist peacefully”. Therefore, we emphasize that it is very important for kidney transplant patients to adhere to daily medication, once the amount of immunosuppressive drugs in the body is not enough, the immune cells will rise up and “aggressively” kill the precious new kidney. The dosage of immunosuppressants is relatively individualized for each patient. If the transplanted kidney is well-matched, the rejection reaction will be relatively weak, and the dosage will be smaller. At present, for kidney transplant patients, both domestic and imported immunosuppressants are publicly funded, with different reimbursement ratios in different provinces and cities. In the case of domestic drugs, for example, lighter weight patients may spend $3-6,000 per month in the first year, but heavier patients will need more than $5-9,000. These drugs are available in major cities across the country. Generally speaking, there is no significant difference between the effects of domestic and imported drugs, and unless the patient has a very special physical condition, it is generally recommended to use domestic drugs, which will be less economically burdensome. The most commonly used immunosuppressants are tacrolimus (FK-506, sometimes doctors say FK, or 506) and cyclosporine, which patients are required to take twice a day, usually at 8:00 am and 8:00 pm. The absorption of tacrolimus is affected by diet, so it is usually taken after or 1-2 hours before a meal, while cyclosporine is not affected by this. Occasional missed doses are unavoidable due to long-term medication, but the drop in blood levels caused by missed doses can directly harm the kidneys. Therefore, if the drug is found to be missed, if it is within 2~3 hours, make up the drug immediately; if it is found after 5~6 hours, the patient should make up half of the dose and not take it at the original dose, so that the concentration will be too high after the next dose and side effects will occur.