Esmolol is a drug that is widely used as a beta1-blocker, which can lower heart rate, lower blood pressure, and sedation, and this drug is still very widely used. The question of its dosage also depends on the patient’s condition. The first prevention of cardiovascular reactions to tracheal intubation, can be intravenous application of 1mg/kg-2mg/kg two minutes before intubation according to the weight of the patient to convert, in general, per kilogram of body weight is 1mg-2mg intravenous application. for the perioperative period first one-minute loading dose 0.25mg/kg-0.5mg/kg intravenous application, after giving four minutes maintenance dose from 0.05mg/kg- Each increase should be preceded by a loading dose. For the treatment of rapid supraventricular arrhythmias, a loading dose of 0.5 mg/kg-min may be given, plus a maintenance dose, the maintenance dose being the same, gradually increasing to 0.2 mg/kg-min, which is the dosage of Esmolol.