Chlormequat chloride is mainly used for the treatment of thrombocythemia, which is now a first-line therapeutic drug. Chlormequat chloride has a strong anti-platelet aggregation effect, mainly through the inhibition of bone marrow megakaryocyte maturation to achieve the effect of platelet reduction, small doses can reduce human platelets and does not affect the white blood cell count. Common adverse reactions are palpitations, diarrhea, abdominal pain, dyspnea, headache, etc., with cardiovascular and pulmonary toxicity, and there is a risk of bleeding, during the use of the drug should be closely observed for adverse reactions, if there is any discomfort immediately notify the doctor or go to the hospital, do not take the drug on their own, the use of the drug should be under the guidance of a physician or pharmacist. The use of this drug needs to be adjusted weekly dosage until the platelet level is adjusted to the appropriate level of the dose, so patients need to be regular follow-up, and testing of routine blood, liver and kidney function and so on.