Phenoxybenzamine Hydrochloride Tablets

Pharmacological action Phenoxybenzamine hydrochloride tablets are long-acting alpha-receptor blockers (alpha 1, alpha 2). They act on postganglionic alpha adrenergic receptors, prevent or reverse the effects of endogenous or exogenous catecholamines, dilate peripheral blood vessels, and increase blood flow. Blood pressure drops slightly when lying down, and drops significantly when standing upright. A drop in blood pressure can reflexively cause an increase in heart rate. Carcinogenicity, mutagenicity, and reproductive toxicity In vitro Ames (Ames, to check for carcinogens) experiments on mouse lymphomas showed that phenoxybenzamine hydrochloride has mutagenic activity; the mouse micronucleus test (micronucleus test) did not show that this product has mutagenic activity. Continuous intraperitoneal injection of phenoxybenzamine hydrochloride in rats or mice can cause peritoneal sarcoma. Long-term oral administration in rats can cause gastrointestinal malignancies, most of which are non-glandular gastric malignancies. In chronic oral experiments, the incidence of ulcerative or erosive gastritis in rats was high, which was related to the drug effect. No research results on the effect of phenoxybenzamine hydrochloride on reproduction have been found.

The main ingredients and chemical name of this product are: N-(1-methyl-2-phenoxyethyl)-N-(2-chloroethyl)benzylamine hydrochloride. Molecular formula C18H22ClNOHCl Molecular weight: 340.29

This product is white tablets.

1. Treatment and preoperative preparation for pheochromocytoma. 2. Peripheral vascular spasm. 3. Urinary retention caused by prostatic hyperplasia.

Dosing should be individualized, and the dosage should be adjusted according to clinical response and the content of catecholamines and their metabolites in urine. Initially, 10 mg once a day, twice a day, and increase by 10 mg every other day until the expected clinical efficacy is achieved or mild adverse reactions of alpha receptor blocking occur. Maintain at 20-40 mg twice a day.

Common symptoms include postural hypotension, nasal congestion, dry mouth, pupil constriction, reflex tachycardia and gastrointestinal irritation. Rare symptoms include confusion, fatigue, headache, impotence, drowsiness, and occasionally angina pectoris and myocardial infarction.

1. Hypotension. 2. Angina pectoris, myocardial infarction. 3. Allergic to this product.

Precautions for children: Oral administration, start with 0.2 mg per kg of body weight, twice a day; or 6-10 mg per square meter of body surface area, once a day. Increase the dose every 4 days until the effect is achieved. The maintenance dose is 0.4-1.4 mg per kg of body weight or 12-36 mg per square meter of body surface area, taken orally in 3-4 times. Precautions for pregnancy and lactation: The effect of this product on pregnancy has not been fully studied, and it can only be used by pregnant women when it is very necessary. It is not known whether this product is secreted through breast milk, but for the sake of caution, breastfeeding women should choose to stop taking the drug or stop breastfeeding. Precautions for the elderly: It is not clear yet. However, the elderly are sensitive to its antihypertensive effect, are prone to hypothermia, and have poor renal function, so they should be cautious when using this product.

1. When used in combination with sympathomimetic amines, the pressor effect is weakened or eliminated; 2. When used in combination with guanethidine, orthostatic hypotension is likely to occur; 3. When used in combination with diazoxide, it antagonizes the latter's inhibitory effect on insulin release; 4. This product can block the hyperthermia caused by L-norepinephrine, and can also block the hypothermia caused by reserpine.

Keep away from light and store in sealed container.

5 mg

24 months