GUANETHIDINE SULFATE

GUANETHIDINE SULFATE 속성

GUANETHIDINE SULFATE C화학적 특성, 용도, 생산

개요

Guanethidine is an antihypertensive compound that competes with norepinephrine for transport into presynaptic terminals of adrenergic neurons by the norepinephrine transporter. Once guanethidine has entered the nerve, it becomes concentrated in synaptic vesicles, depleting endogenous norepinephrine, and thus, reducing the release of norepinephrine in response to action potentials. Guanethidine’s actions are restricted to peripheral nerve terminals because its basic guanidine group does not allow passage through the blood brain barrier. Its use has been explored in the relief of chronic pain caused by complex regional pain syndrome.

화학적 성질

GUANETHIDINE SULFATE is colourless, crystalline powder

용도

Antihypertensive.

정의

ChEBI: A organic sulfate salt obtained from guanethidine and sulfuric acid in a 1:1 ratio.

일반 설명

Guanethidinemonosulfate, [2-(hexahydro-1 (2H)-azocinyl)ethyl]guanidinesulfate (Ismelin sulfate), is a white, crystalline materialthat is very soluble in water. It was one of a series ofguanidine compounds prepared in the search for potent antitrypanosomalagents. There is an absence of CNS effects,such as depression, because the drug is highly polar anddoes not easily cross the blood-brain barrier. Guanethidinemonosulfate produces a gradual, prolonged fall in bloodpressure. Usually, 2 to 7 days of therapy are required beforethe peak effect is reached, and usually, this peak effectis maintained for 3 or 4 days. Then, if the drug is discontinued,the blood pressure returns to pretreatment levelsover a period of 1 to 3 weeks. Because of this slow onsetand prolonged duration of action, only a single daily doseis needed.

Mechanism of action

Guanethidine is an adrenergic neuronal blocking agent that produces a selective block of peripheral sympathetic pathways by replacing and depleting norepinephrine stores from adrenergic nerve endings, but not from the adrenal medulla. It prevents the release of norepinephrine from adrenergic nerve endings in response to sympathetic nerve stimulation. The chronic administration of guanethidine results in an increased sensitivity of these effector cells to catecholamines. Following the oral administration of usual doses of guanethidine, depletion of the catecholamine stores from adrenergic nerve endings occurs at a very slow rate, producing a more gradual and prolonged fall in systolic blood pressure than in diastolic pressure. Associated with the decrease in blood pressure is an increase in sodium and water retention and expansion of plasma volume (edema). If a diuretic is not administered concurrently with guanethidine, tolerance to the antihypertensive effect of the guanethidine during prolonged therapy can result.

Pharmacokinetics

Guanethidine is incompletely absorbed from the GI tract and is metabolized in the liver to several metabolites, including guanethidine N-oxide (from flavin mononucleotide). These metabolites of guanethidine are excreted in the urine and have less than 10% of its hypotensive activity. The amount of drug that reaches the systemic circulation after oral administration is highly variable from patient to patient and may range from 3 to 50% of a dose. Guanethidine accumulates in the neurons with an elimination half-life of 5 days.

Clinical Use

Guanethidine monosulfate is metabolized by microsomalenzymes to 2-(6-carboxyhexylamino)ethylguanidine andguanethidine N-oxide . Both metabolites havevery weak antihypertensive properties. Guanethidine monosulfateis taken up by the amine pump located on theneuronal membrane and retained in the nerve, displacingnorepinephrine from its storage sites in the neuronal granules.The displaced norepinephrine is metabolized to homovanillicacid by mitochondrial MAO, depleting the nerveending of the neurotransmitter. The usefulness of guanethidinemonosulfate also resides in the fact that once it is takenup by the nerve, it produces a sympathetic blockade by inhibitingrelease of nonepinephrine that would occur on neuronalmembrane response to stimulation29 by the nerveaction potential. Guanethidine monosulfate stored in thegranules is released by the nerve action potential but hasvery low intrinsic activity for the adrenergic receptors on thepostjunctional membrane. Moderate doses for a prolongedperiod or large doses may produce undesirable side effectsby causing neuromuscular blockade and adrenergic nerveconduction blockade.

부작용

Adverse effects of guanethidine frequently are dose related, including dizziness, weakness, lassitude, and syncope resulting from postural or postexercise hypotension. A hot environment (i.e., a hot bath) may aggravate postural hypotension. Patients should be warned about possible orthostatic hypotension and about the effect of rapid postural changes on blood pressure (e.g., arising in the morning) that may cause fainting, especially during the initial period of dosage adjustment. Sodium retention (edema) usually is controlled by the coadministration of a diuretic.

Drug interactions

Diuretics and other hypotensive drugs can potentiate the hypotensive effects of guanethidine. Reportedly, MAO inhibitors antagonize the hypotensive effect of guanethidine. Oral sympathomimetic, nasal decongestants, and other vasopressor agents should be used cautiously in patients receiving guanethidine, because guanethidine may potentiate their pressor effects. The mydriatic response to ophthalmic administration of phenylephrine is markedly increased in patients receiving guanethidine either ophthalmically or orally.
Tricyclic antidepressants and some phenothiazines block the uptake of guanethidine into adrenergic neurons and, thus, prevent the hypotensive activity of guanethidine. Orthostatic hypotension may be increased by concomitant administration of alcohol with guanethidine, and patients receiving guanethidine should be cautioned to limit alcohol intake.

GUANETHIDINE SULFATE 준비 용품 및 원자재

원자재

준비 용품

GUANETHIDINE SULFATE 공급 업체

공급자	전화	이메일	국가	제품 수	이점
Hebei Mojin Biotechnology Co., Ltd	+8613288715578	sales@hbmojin.com	China	12470	58
career henan chemical co	+86-0371-86658258	sales@coreychem.com	China	29914	58
Hebei Guanlang Biotechnology Co., Ltd.	+86-19930503282	alice@crovellbio.com	China	8829	58
Chongqing Chemdad Co., Ltd	+86-023-6139-8061 +86-86-13650506873	sales@chemdad.com	China	39916	58
TargetMol Chemicals Inc.	+1-781-999-5354 +1-00000000000	marketing@targetmol.com	United States	19892	58
Hubei Ipure Biology Co., Ltd	+8613367258412	ada@ipurechemical.com	China	10326	58
Hefei TNJ Chemical Industry Co.,Ltd.	0551-65418671	sales@tnjchem.com	China	34571	58
ANHUI WITOP BIOTECH CO., LTD	+8615255079626	eric@witopchemical.com	China	23556	58
Shaanxi Dideu Medichem Co. Ltd	+86-029-89586680 +86-18192503167	1026@dideu.com	China	9126	58
AFINE CHEMICALS LIMITED	+86-0571-85134551	info@afinechem.com	China	15396	58

GUANETHIDINE SULFATE 관련 검색: