Children with blood disorders basically need to take medication every day, so how can we use the medication reasonably and make it work better? The following is an introduction to parents on the usage of several commonly used drugs. 1- 6-Mercaptopurine (6-MP): It is the main drug for the treatment of children with acute lymphoblastic leukemia (especially the maintenance period) and should be taken every day during the maintenance period. But must remember: two hours before taking the drug and one hour after taking the drug, do not eat food, fruit (including fruit juice), and do not drink milk, yogurt and other dairy products. 2, cotrimoxazole: The drug is a very important adjuvant drug during chemotherapy for children with leukemia, is used to prevent “Pneumocystis carinii pneumonia”, although the incidence of the disease is very low, but once the mortality rate is very high, taking the method for three days a week, stop four days, adhere to take this drug until 3-6 months after the drug. It has been reported that cotrimoxazole can aggravate the toxicity of MTX, so the drug is not taken in the course of high-dose MTX; during the maintenance period, parents had better arrange the drug not to be applied on the same day with MTX. As cotrimoxazole is excreted from the kidneys, it is easy to form sulfonamide crystals in an acidic environment, which can damage the kidneys and lead to stones and hematuria, so drink more water when taking the drug and do not take it together with vitamin C, juice and other acidic foods. 3, cyclosporine (CsA): the main drug for children with aplastic anemia, the full amount of this drug should be divided into two regular doses, when taking this drug should avoid grapefruit juice, high potassium food, fried greasy food and potassium diuretics, nifedipine, etc.. For cyclosporine oral solution, the required amount of medicine should be taken correctly with a special pipette, preferably diluted with orange or apple juice, or diluted with soft drinks according to individual tastes (but please do not dilute with grapefruit juice), and taken immediately after thorough stirring. This product should be stored away from light and used up within 2 months after opening.