Patients with membranous nephropathy usually take tacrolimus for about two and a half years at the longest. Tacrolimus is a kind of immunosuppressant, which can be used in the treatment of membranous nephropathy. The dosage of tacrolimus is relatively large at the beginning of the treatment, and after half a year of urinary protein reduction, the dosage can be reduced by half, and the dosage is usually maintained for one to two years. The specific dosage time needs to be determined according to the reduction of urine protein and the reduction of phospholipase A2 receptor antibody. If there is no reduction of urine protein or serious side effects after using the drug, the drug may be discontinued at any time, if the response is good, the drug is usually used for six months to one and a half years, and the maximum duration of the drug is about two and a half years. The use of the drug may cause adverse reactions such as high blood pressure, angina, palpitations (rapid heartbeat, often accompanied by panic), seepage, etc. It is contraindicated for those who are allergic to the product. Due to the small range of blood levels during tacrolimus treatment, regular monitoring of blood levels is required. The drug is a prescription drug and should be used in strict compliance with medical advice.