I. Diuretics, representative drugs and characteristics are as follows 1. Hydrochlorothiazide: Used alone for mild, early hypertension or in combination with other antihypertensive drugs for various types of hypertension. The effect is mild, not easy to produce tolerance, easy to be accepted by patients. Less adverse reactions, long-term use of drugs can cause hypokalemia, should be appropriate potassium supplementation. 2, indapamide antihypertensive mechanism in addition to sodium diuresis, but also with its vasodilator effect and its blocking calcium channels, reducing Ca2+ inward flow. It is a strong, long-acting antihypertensive drug, suitable for mild and moderate hypertension. Second, angiotensin-converting enzyme inhibitors, representative drugs and characteristics are as follows 1, captopril: moderate antihypertensive, rapid, brief, not accompanied by reflex heart rate acceleration. It can prevent and reverse vascular smooth muscle proliferation and left ventricular hypertrophy, and has no significant effect on lipid metabolism. It is one of the drugs of choice for mild to moderate hypertension or renal hypertension. Adverse effects: ① rash, angioneurotic edema, loss of taste and first dose hypotension. ②Irritating dry cough. ③A few patients may develop proteinuria, hyperkalemia, renal impairment, etc. 2.Enalapril: strong and long-lasting antihypertensive effect. Adverse reactions are lighter than captopril. It is used for the treatment of hypertension and heart failure. Angiotensin II (AT1) receptor blocking drugs, representative drugs and characteristics are as follows 1, Crosartan is an orally effective non-peptide AT1 receptor blocking drug, selectively binding to AT1 receptors, blocking the action of Ang II, producing antihypertensive effect. It is used clinically for ① treatment of all types of hypertension. ②Protective effect in patients with hypertension and diabetes combined with renal insufficiency. ③ hyperuricemia and promote uric acid excretion. Adverse effects are rare. May cause hypotension, gastrointestinal discomfort, headache, dizziness, etc. 2.Valsartan is an AT1 receptor blocking drug, which is characterized by fast onset of action, strong effect, long maintenance time and low incidence of adverse reactions. Fourth, β-blocking drugs, representative drugs and characteristics are as follows 1, metoprolol is selective β1 receptor blocking drugs, low dose mainly on the heart, the effect on the bronchial tubes is small, relatively safe for patients with obstructive lung disease. 2. Carvedilol is an α and β receptor blocker, which is two to four times stronger than propranolol and can be used to treat patients with mild to moderate hypertension or hypertension with renal insufficiency and diabetes mellitus. Fifth, calcium antagonists, representative drugs and characteristics are as follows 1, nifedipine is the first generation of calcium antagonists. The antihypertensive effect is obvious, but due to the short duration of cardiac pain, generally need to take 3 times a day. Adverse reactions include headache, rapid heartbeat, red face, etc. 2. Loxodren is a long-acting calcium antagonist with a half-life of 35-50 hours, and can be taken once a day to maintain smooth control of blood pressure for 24 hours. In addition, there are other antihypertensive drugs with different antihypertensive mechanisms such as: colistin, reserpine, prazosin, sodium nitroprusside, etc.