Tacrolimus belongs to the class of macrolides, which has a potent inhibitory effect on the body’s immune function, and is used for the prevention or treatment of body rejection after liver and kidney transplantation. Side effects such as pneumonia, hypertension, cardiac arrhythmia, decreased urine output, increased blood glucose, diarrhea, headache, nausea, abnormal sensations, insomnia, rash, leukopenia, arthralgia, hyperkalemia, tinnitus, etc., can be experienced with the use of the drug. The drug should be taken 2 to 3 hours after a meal, 1 hour before a meal, or on an empty stomach. Because hyperkalemia may result from the use of the drug, potassium should not be ingested in large quantities or potassium-preserving diuretics such as aminopterin and amloprim should not be used. The drug interacts with cyclosporine, danazol, acyclovir and other drugs, so you should consult a medical professional before use. It is contraindicated in the following cases: hypersensitivity to the drug or other macrolides, taking cyclosporine, women during pregnancy. Nursing women should stop breastfeeding while using the drug. If you need to use the drug, please be sure to follow the doctor’s instructions strictly under the guidance of the medication, do not self-medication.