Name: | Hydralazine |
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PubChem Compound ID: | 3637 |
Description: | A direct-acting vasodilator that is used as an antihypertensive agent. |
Molecular formula: | C8H8N4 |
Molecular weight: | 160.176 g/mol |
Synonyms: |
C-5068; Hydrallazine; BA 5968; KBio1_000117; Hidralazina [Spanish]; 1(2H)-Phthalazinone hydrazone; HSDB 434; NSC126699; Hidralazina [INN-Spanish]; Hipoftalin.
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Name: | Hydralazine |
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Name (isomeric): | DB01275 |
Drug Type: | small molecule |
Description: | A direct-acting vasodilator that is used as an antihypertensive agent. |
Synonyms: |
Hydralazine hydrochloride
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Brand: | Apresoline |
Brand name mixture: | BiDil(isosorbide dinitrate + hydralazine hydrochloride) |
Category: | Vasodilator Agents, Antihypertensive Agents |
CAS number: | 86-54-4 |
Indication: | For the treatment of essential hypertension, alone or as an adjunct. Also for the management of severe hypertension when the drug cannot be given orally or when blood pressure must be lowered immediately, congestive heart failure (in combination with cardiac glycosides and diuretics and/or with isosorbide dinitrate), and hypertension secondary to pre-eclampsia/eclampsia. |
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Pharmacology: |
A vasodilator, hydralazine works by relaxing blood vessels (arterioles more than venules) and increasing the supply of blood and oxygen to the heart while reducing its workload. It also functions as an antioxidant. It inhibits membrane-bound enzymes that form reactive oxygen species, such as superoxides. Excessive superoxide counteracts NO-induced ...
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Mechanism of Action: |
Although the precise mechanism of action of hydralazine is not fully understood, the major effects are on the cardiovascular system. Hydralazine apparently lowers blood pressure by exerting a peripheral vasodilating effect through a direct relaxation of vascular smooth muscle. It has also been suggested that cyclic 3',5'-adenosine monophosphate (cy...
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Absorption: | Hydralazine is rapidly and extensively absorbed (up to 90%) from the gastrointestinal tract and undergoes extensive first-pass metabolism by genetic polymorphic acetylation. Oral bioavailability of hydralazine is dependent upon acetylator phenotype. Bioavailability is approximately 31% in slow acetylators and 10% in fast acetylators. |
Protein binding: | 87% |
Biotransformation: | Hydralazine, when administered orally, undergoes extensive first-pass metabolism by genetic polymorphic acetylation, which is responsible for a threefold range of oral bioavailability. Intravenously administered hydralazine does not undergo first-pass metabolism and, therefore, is not affected by acetylator phenotype. After the drug reaches the systemic circulation, it is combined with endogenous aldehydes and ketones, including pyruvic acid, to form hydrazone metabolites. The active metabolites, hydralazine acetonide hydrazone and hydralazine pyruvate hydrazone, are equipotent with the parent, hydralazine. |
Route of elimination: | Hydralazine undergoes extensive hepatic metabolism; it is excreted mainly in the form of metabolites in the urine. |
Half Life: | 3 to 7 hours |
Toxicity: | Oral LD50 in rats: 173 and 187 mg/kg |
Affected organisms: | Humans and other mammals |
Drug interaction: |
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