Angiotensin-converting enzyme inhibitors, called ACEI drugs for short, are one of the major classes of antihypertensive drugs, which mainly act on the renin-angiotensin pathway. Its representative drugs are enalapril, ramipril, benazepril, perindopril, and fosinopril, etc. The earliest ACEI drugs developed are called captopril, but the half-life of captopril is relatively short, so captopril needs to be taken several times a day. The later developed drugs are basically long-acting drugs, which can be taken once a day, so that the patient’s compliance will be better.