Diazoxide Also known as antihypertensive and chlorxylazine, it is a quick-acting antihypertensive benzothiazine without diuretic effect. Pressed medicine, it is a white crystalline powder at room temperature. Molecular weight 230.70. Melting point 330~331℃. Soluble in ethanol, slightly soluble in acetone, chloroform, methanol, insoluble in water, easily soluble in sodium hydroxide solution. Odorless. Slightly bitter taste. This product can directly relax vascular smooth muscle, reduce peripheral vascular resistance, and cause blood pressure to drop sharply. When blood pressure is lowered, renal blood flow remains unchanged and cardiac output increases. . It is prepared from 5-chloro-2-acetamido-N-acetylbenzenesulfonamide through high-temperature cyclization.
[Alias] Hyperstat, chloroxylazine, chloroxylazine, Hyperstat
【Function and use】
Diazoxide is a quick-acting antihypertensive drug of the benzothiazine type, which directly relaxes vascular smooth muscle, reduces peripheral vascular resistance, and causes a sharp drop in blood pressure. When blood pressure is lowered, renal blood flow remains unchanged and cardiac output increases.
Diazoxide is a thiazide antihypertensive drug without diuretic effect. It can directly relax the smooth muscle of arterioles and has no effect on veins. The antihypertensive effect is obvious, rapid and lasting, and takes effect within 1 minute after rapid intravenous injection. The effect reaches its peak in 2 to 5 minutes and lasts for 4 to 12 hours. It can reflexively excite sympathetic nerves, causing increased heart rate, enhanced myocardial contractility, increased cardiac output, keeping renal blood flow basically unchanged, and increasing plasma renin activity. This product can directly inhibit the secretion of insulin by pancreatic beta cells, inhibit peripheral glucose utilization, promote liver glucose production, and increase blood sugar.
Diazoxide is mainly suitable for hypertensive crisis and hypertensive encephalopathy. It can also be used for idiopathic hypoglycemia in young children and severe hypoglycemia caused by islet cell tumors.
It is also suitable for emergency treatment of hypertensive crisis and can still be used as usual for hypertensive patients with renal insufficiency. This product also has the effect of inhibiting insulin secretion, thereby increasing blood sugar concentration, and can be used to treat idiopathic hypoglycemia in young children or severe hypoglycemia caused by islet cell tumors.
【Pharmacodynamics】
This medicine is a vasodilator. Its main pharmacological effect is to directly dilate arterioles, and secondly, it may inhibit α-adrenergic receptors, causing a decrease in peripheral vascular resistance and blood pressure. Has no effect on veins. It can increase heart rate, stroke volume and cardiac output. No significant effect on renal blood flow.
This drug can also inhibit the secretion of insulin by pancreatic beta cells, which can cause elevated blood sugar and hyperuricemia.
Relaxes vascular smooth muscle and reduces peripheral vascular resistance, which can lead to a sharp drop in blood pressure. After taking the medicine, the blood pressure reduction peak can occur within 5 minutes, and the blood pressure can be reduced to normal, and can be maintained for 2 to 18 hours or longer. It does not reduce cardiac output when lowering blood pressure and does not affect the blood flow supply to the brain, kidneys and heart. Clinically used for the control of hypertensive crisis. It can still inhibit the secretion of insulin and is used for severe hypoglycemia caused by childhood idiopathic hypoglycemia and pancreatic beta cell tumors.
[Pharmacokinetics]
It takes effect 30 minutes to 1 hour after oral administration and can maintain its effect for 4 to 5 hours. However, after this drug enters the blood, more than 90% is quickly bound to plasma proteins: only a small part of the free diazoxide acts on the blood vessels, causing the dilation of the arterioles. Therefore, oral antihypertensive efficacy is poor, so rapid intravenous administration is more effective. Blood pressure drops to the lowest level 1 to 5 minutes after intravenous injection. Maintenance effect is 1 to 6 hours. Diazoxide is primarily excreted unchanged via the kidneys.
[Dosage and usage]
1. Rescue hypertensive crisis: rapid intravenous injection, 200 to 400 mg each time, complete within 10 to 20 seconds. If the antihypertensive effect is not satisfactory, the injection can be repeated once within 0.5 to 3 hours, with the total daily dose not exceeding 1,200 mg. During injection, dissolve this product in a special solvent and inject in the supine position. After the symptoms are relieved, oral antihypertensive drugs are used for maintenance.
2. Treatment of hypoglycemia. Oral administration: 400 to 800 mg per day for adults, 1 to 3 mg/kg for children, 2 to 3 times a day.
3. Rapid intravenous injection: 200 to 400 mg or 5 mg/(kg·time) for one time, complete the injection within 15 to 20 seconds in the supine position. If necessary, another injection can be given within 0.5 to 3 hours, and the total dose per day shall not exceed 1200 mg. Combined use of diuretics can prevent water and sodium retention and have a better blood pressure lowering effect. Generally, 30 to 60 minutes before injecting this drug, 20 to 40 mg of furosemide should be injected each time.
4. Dissolve this product in a special solvent and inject it intravenously quickly with the patient in the supine position. After the symptoms are relieved, oral antihypertensive drugs are taken for maintenance. Rapid intravenous injection: 200~400mg/time, complete in 15~20s. For hypertensive crisis, re-injection can be given once every 0.5 to 3 hours. The total amount does not exceed 1200mg/d. Children, 5mg/kg.
[Adverse reactions and precautions]
1. Adverse reactions such as palpitations, facial flushing, headache, insomnia, chest pain, nausea, vomiting, constipation, abdominal discomfort, abnormal hearing, arrhythmia, elevated blood sugar, elevated blood uric acid, and hypotension may occur after taking diazoxide.
2. It can cause water and sodium retention, and repeated use can cause edema and congestive heart failure. If re-administration is needed, 20 mg of furanilide should be slowly injected intravenously 30 to 60 minutes before intravenous injection to prevent water and sodium retention.
3. This product will cause a burning sensation when injected intravenously. Avoid leakage outside the blood vessels and cause local pain and inflammation.
4. People who have injected this product multiple times or patients with diabetesFor those with diabetes, insulin or oral hypoglycemic drugs can be used to control blood sugar.
5. It should not be used by women with congestive heart failure, diabetes, renal insufficiency, severe hypertension and lactating women.
6. Diazoxide should not be used in combination with thiazide diuretics.
7. This product should not be used in conjunction with other drugs and infusions.
8. It has many adverse reactions, so it should only be used when other antihypertensive drugs are ineffective.
[Dosage Form] Injection: 300mg, with special solvent 20mL; capsule: 50mg, 100mg.
【Diazoxide Poisoning】
【Diagnosis Points】
1. Adverse reactions:
Dizziness, headache, drowsiness, insomnia, vertigo, tinnitus, nausea, vomiting, abdominal pain, diarrhea, constipation.
2. Symptoms of poisoning
(1) Myocardial ischemia, angina pectoris, atrial or ventricular arrhythmia, and occasional acute myocardial infarction.
(2) It can cause water and sodium retention, edema, and induce congestive heart failure.
(3) Hypotension, dizziness, shock.
(4) Cerebral infarction, loss of consciousness, paralysis, insanity, fear, and anxiety.
(5) Long-term use may cause an increase in blood sugar, or even hyperglycemic ketoacidosis coma or hyperglycemic non-ketotic hyperosmolar coma.
(6) Long-term and repeated use may cause blood volume expansion, resulting in papilledema, blurred vision, and transient cataracts.
(7) There may be leukopenia, eosinophilia and thrombocytopenia.
【Processing Principles】
1. If poisoning or adverse reactions occur after taking a large amount of medication, the medication should be stopped immediately.
2. Symptomatic treatment, such as hypotension with vasopressors; cerebral infarction can improve cerebral blood supply; diabetic ketosis and non-ketotic coma, while lowering blood sugar, correct ketone poisoning or reduce osmotic pressure; leukopenia can use leukocyte-raising drugs, etc.
The above information was collected and compiled by Wang Xiaonan of ChemicalBook.
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