Isoproterenol, is often used clinically as a rescue drug. It is mainly used in patients with cardiogenic shock or infectious shock, and in patients with complete atrioventricular block or cardiac arrest. General intravenous use of isoprenaline: In patients in cardiac arrest, 0.5-1 mg of isoprenaline can be injected directly into the cardiac chambers, or in the case of intravenous drip, often with 200-300 ml of 5% dextrose added to 0.5-1 mg of isoprenaline for slow intravenous drip. In case of micropumping patients can be pumped with isoproterenol 3mg plus saline 44ml at a continuous rate of 1ml/h. However, it is important to note that isoproterenol is contraindicated in patients with myocardial infarction or pheochromocytoma.