Antimetabolic drugs. The main indication is acute myeloid leukemia which is ineffective to conventional treatment. It is also used for breast cancer, melanoma, intestinal cancer and so on. The main manifestations of toxicity were leucopenia, thrombocytopenia and anemia. Nausea and vomiting are common adverse reactions. Symptoms can be improved by continuous infusion for a long time, or antiemetic agents can be used 24 to 48 hours before treatment. Other toxic effects were diarrhea, neuromuscular disorders, fever, hypotension and rash. The preparation is freshly prepared 3-4h before use.