Approved date: January 29, 2007
Date of revision: October 1, 2010
October 01, 2012
November 30, 2015
Phenolbenzyl hydrochloride tablets instructions
Please read the instructions carefully and use them under the guidance of a physician.
Generic name: phenoxybenzamine hydrochloride tablets
English name: Phenoxybenzamine Hydrochloride Tablets
Chinese Pinyin: Yansuan Fenbianming Pian
[Ingredients] The main component of this product is: phenoxybenzamine hydrochloride. Its chemical name is: N-(1-methyl-2-phenoxyethyl)-N-(2-chloroethyl)benzylamine hydrochloride.
Molecular formula: C18H22ClNO·HCl
Molecular weight: 340.29
【Properties】 This product is a white film or a film-coated tablet, which is white after removing the coating.
1. Treatment and preoperative preparation of pheochromocytoma.
2. Peripheral vasospasm.
3. Urinary retention caused by benign prostatic hyperplasia.
Dosing should be adjusted according to the clinical response and the content of catecholamine and its metabolites in urine according to the individualization principle. Start with 10 mg (1 tablet) once a day, 2 times a day, and increase 10 mg (1 tablet) every other day until the expected clinical effect is obtained, or there is a slight alpha receptor blockade. It is maintained twice a day at 20 to 40 mg (2 to 4 tablets).
[Adverse reactions] Common orthostatic hypotension, nasal congestion, dry mouth, dilated pupils, accelerated heartbeat and gastrointestinal irritation. Uncommon ambiguity, burnout, headache, impotence, lethargy, can even cause angina and myocardial infarction.
1. Low blood pressure.
2. Angina pectoris, myocardial infarction.
3. Those who are allergic to this product.
1. Animal experiments have shown that long-term oral administration can cause gastrointestinal cancer.
2. When the blood supply to the brain is insufficient, it is necessary to pay attention to the blood pressure drop, which may aggravate cerebral ischemia.
3. Compensatory heart failure can cause a reflexed heartbeat to accelerate, resulting in decompensation of cardiac function.
4. Patients with coronary heart disease can suffer from angina due to accelerated heart rate.
5. Renal insufficiency may cause further damage to renal function due to hypotension and renal ischemia.
6. Upper respiratory tract infection may be aggravated by nasal congestion.
7. Blood pressure should be measured regularly during medication.
8. When starting treatment of pheochromocytoma, it is recommended to regularly measure urinary catecholamines and their metabolites to determine the amount of drug.
9. Reflex heart rate acceleration can be added with beta blockers; with food or milk to reduce gastrointestinal irritation.
10. When phenoxybenzamine is excessive, epinephrine cannot be used, otherwise it will further aggravate hypotension, which is called the reversal effect of adrenaline.
[Pregnant women and lactating women]
The effect of this product on pregnancy has not been fully studied, and this product can only be used when it is necessary for pregnant women. It is not known whether this product is secreted by milk, but for the sake of caution, lactating women should choose to stop or stop breastfeeding.
Oral, starting at 0.2 mg per kilogram of body weight, 2 times a day; or 6 to 10 mg per square meter of body surface area, once a day. It will be incremented once every 4 days until the effect is achieved. The maintenance amount is 0.4-1.4 mg per kilogram of body weight per day or 12 to 36 mg per square meter of body surface area, and is orally administered 3 to 4 times.
[Geriatric medication] is not clear. However, the elderly are sensitive to their antihypertensive effects, prone to low temperature, and poor renal function. Care should be taken when applying this product.
1. In combination with sympathomimetic amines, the boosting effect is weakened or disappeared.
2. In combination with guanethidine, orthostatic hypotension is prone to occur.
3. Antagonize the latter's inhibition of insulin release when used in combination with diazoxide.
4. This product can block the hyperthermia caused by left-handed norepinephrine, and can also block hypothermia caused by reserpine.
If there is orthostatic hypotension, dizziness, fatigue, tachycardia, vomiting, lethargy or shock during drug overdose, the drug should be discontinued immediately and anti-shock therapy should be given. The patient is placed in the lower leg and the high position, and the brain oxygen supply is restored. The leggings and abdominal pressure are used to reduce the hypotensive reaction and shorten the drug reaction time. The severe hypotensive reaction requires intravenous infusion of the armor. Adrenaline heavy tartrate, antagonizing the alpha receptor blockade of phenoxybenzamine hydrochloride.
【Pharmacology and Toxicology】
Pharmacological action Phenylbenzamine hydrochloride tablets are long-acting α-blockers (α1, α2). It acts on post-ganglionic alpha adrenergic receptors to prevent or reverse the action of endogenous or exogenous catecholamines, causing peripheral blood vessels to dilate and increase blood flow. The blood pressure drops slightly in the supine position and can drop significantly when standing upright. A drop in blood pressure can reflect the increase in heart rate.
Carcinogenic, mutagenic and reproductive toxicity in mouse lymphomas Ames (Ames, carcinogens) experiments showed that phenoxybenzamine hydrochloride has mutagenic activity; mouse micronucleus test did not show mutagenicity of this product active. Continuous injection of phenoxybenzamine hydrochloride into the peritoneal cavity of rats or mice can cause peritoneal sarcoma. Long-term oral administration of rats can cause gastrointestinal malignancies, the vast majority of which are non-glandular malignant tumors of the stomach. In chronic oral experiments, the incidence of ulcerative or erosive gastritis in rats is high, which is related to drug action. No results were found on the effects of phenoxybenzamine hydrochloride on reproduction.
After oral administration, about 30% of phenoxybenzamine hydrochloride is absorbed in the gastrointestinal tract, and the half-life (t1/2) is about 24 hours, and the effect lasts for 3 to 4 days. This product is metabolized in the liver. Most drugs are excreted from the kidneys and bile within 24 hours, and a small amount is retained in the body for several days.
[Storage] shading, sealed (10 ~ 30 ° C) preservation.
[Packing] Aluminum-plastic packaging, 24 pieces per box; 48 pieces per box. Packed in aluminum foil, 20 pieces per box.
[Validity Period] 24 months
[Executive Standards] "Chinese Pharmacopoeia" 2015 Edition 2
[Approval No.] National Drug Standard H44021427
Company Name: Guangdong Pi Di Pharmaceutical Co., Ltd.
Production address: No. 66, Pidi Avenue, Yueshan Town, Kaiping City, Guangdong Province
Postal code: 529331
Phone number: (0750) 2789348 400-8899-328 (National Service Phone)
Fax number: (0750) 2789348