In the early stage of medication: through sodium and drainage, the extracellular fluid and blood volume are reduced and blood pressure is lowered.

Long-term medication: continuous reduction of intracellular Na concentration → reduction of intracellular Ca2 concentration → relaxation of vascular smooth muscle and dilation of blood vessels

Good oral absorption, mild and long-lasting antihypertensive effect

Long-term use: tolerance to hypokalemia, hyperuricemia, glucose and lipid metabolism disorders (patients with hyperlipidemia)

1. The degree of blood pressure reduction is highly positively correlated with the original blood pressure. It has no obvious antihypertensive effect on people with normal blood pressure. The effect is short-lived and can cause severe fluctuations in blood pressure. 2. Good oral absorption and quick onset of effect: 1-5 minutes for sublingual administration - effective for the treatment of variant angina pectoris and hypertensive crisis; 30-60 minutes for oral administration - effective for the treatment of mild and moderate hypertension; 3 Can cause reflex heart rate ↑ - combined with beta-blockers. 4 Renin secretion↑—Combined use of thiazide diuretics

1 More selective for vascular smooth muscle 2 Orally absorbed agents have higher bioavailability (>90%), mild onset of action, gradual blood pressure reduction, and long-lasting efficacy. 3 Mild to moderate hypertension; stable and variant angina pectoris

1 Kidney: Juxtaglomerular apparatus β1 secretes renin↓——renin-angiotensin-aldosterone system↓——plasma angiotensin II level↓ 2Heart: β1 receptor↓——cardiac output↓ 3 Center: β receptors - central excitatory neurons ↓ - peripheral sympathetic tone ↓ - vascular resistance ↓ 4. Promote the production of prostacyclin

Suitable for mild hypertension when used alone Combined with diuretics and vasodilators, the efficacy is also good in patients with moderate and severe hypertension, angina pectoris, arrhythmia, and high renin activity.

1. Bradycardia, bronchospasm, nausea, diarrhea, fatigue 2 Mental side effects: dreams, hallucinations, insomnia, depression. 3 Start with a small dose (40-60mg/day), and generally use a larger dose (200mg/day) to achieve the antihypertensive effect; it is not advisable to stop suddenly after long-term use (drug withdrawal syndrome) 4. Patients with cardiomegaly, heart failure, and asthma should not use it. Great individual differences

Atenolol, carvedilol, labetalol (α1/β receptor blockers)

antihypertensive mechanism

Clinical application

Adverse reactions

Similar drugs

Clinical application

Buck characteristics

center 1 Selective stimulation of secondary neurons in the nucleus of the solitary tract of the oblongata (inhibitory) - Excitation of postsynaptic membrane α2 receptors ↑ - Peripheral sympathetic nerve activity ↓ - Blood pressure ↓ 2 Imidazoline receptors at the rostral end of the ventrolateral medulla oblongata↑——Peripheral sympathetic nerve activity↓——Blood pressure↓ Periphery Stimulates α2 receptors in presynaptic membrane of peripheral sympathetic nerve terminals↑——NA release↓ (negative feedback)——blood pressure↓

For moderate hypertension, it is usually used when other antihypertensive drugs are ineffective. opioid withdrawal

Dry mouth, constipation, drowsiness, depression, impotence, rebound, etc.

Sodium nitrosoferricyanide—when in contact with vascular endothelial cells or red blood cells—releases NO—activates vascular smooth muscle cells GC—cGMP↑—vasodilation—blood pressure↓

hypertensive crisis

Quick onset of action, not absorbed after oral administration, intravenous administration

Nausea, vomiting, palpitations, uneasiness, sweating, etc. (caused by excessive blood pressure lowering and disappear after discontinuation of medication). Sulfur cyanide accumulation poisoning. It is easily damaged when exposed to light (the instillation solution should be freshly prepared and protected from light).

Selectively blocks postsynaptic membrane α1 receptors, has a very weak effect on presynaptic membrane α2 receptors, and does not affect negative feedback

‘First dose phenomenon’, orthostatic hypotension

1. Complete oral absorption, rapid onset of action, and powerful antihypertensive effect; 2. Reflexively stimulate sympathetic nerves when lowering blood pressure 3. Long-term use (several months, 10mg/day) may also cause hirsutism. 4. Mainly used for severe hypertension and hypertension complicated by renal failure.

Increased heart rate, arrhythmia, skin flushing; Water and sodium retention causes weight gain and lower limb edema