Vasodilator injection drugs include nitroglycerin, captopril, nifedipine, phentolamine and so on, which can dilate cardiac or peripheral skin blood vessels, and have the effect of relieving ischemic symptoms and lowering blood pressure on the body, but need to pay attention to contraindications. 1. Captopril injection: belongs to angiotensin converting enzyme inhibitor. It needs to be used with caution during lactation and pregnancy. (1) Effects on human body: it can expand blood vessels and lower blood pressure, treat heart failure, hypertensive emergencies and so on. (2) Contraindications: prohibited for those who are allergic to the drug. It is forbidden to use during lactation and pregnancy. 2. Nifedipine injection: calcium channel antagonist. (1) Effects on human body: It can treat hypertensive crisis. (2) Contraindications: drug allergy, hypotensive shock, severe aortic stenosis, pregnancy and lactation are prohibited. In addition, α-blockers such as phentolamine also have a certain vasodilator effect, but are mainly used in the treatment of hypertensive crisis phase caused by pheochromocytoma; injection of captopril, nifedipine and other drugs need to be carried out by a physician under the guidance of a clinician, unauthorized use of drugs is prohibited.