Methotrexate dosage reduction depends on the specific situation, if there is a serious adverse reaction needs to be stopped immediately, if the condition has improved, you can consider a gradual reduction of the dosage, including reducing the frequency of taking, single dose and so on. Methotrexate inhibits DNA biosynthesis and is used in the treatment of all types of acute leukemia, malignant hyperemesis gravidarum, breast cancer, head and neck cancer, bronchial lung cancer and other diseases. The drug is associated with hepatic and renal impairment, bone marrow suppression, mucosal damage, allergic reactions, and hypogammaglobulinemia, and needs to be discontinued immediately if there is a significant decrease in blood cell counts and toxic epidermal necrolysis. If the condition of rheumatoid, malignant tumors, etc. improves after methotrexate treatment, after maintaining the treatment for a period of time, you can consider reducing the dosage of the drug, but the dosage reduction should be gradual, slowly reduce the number of times and the dosage of the drug, and must not be too hasty, so as to avoid recurrence of the disease. The use of methotrexate should be under the guidance of medical professionals, do not use the drug on your own.