Hydralazine Hydrochloride

Severe essential hypertension when the drug cannot be given orally or when there is an urgent need to lower blood pressure.

Hypersensitivity to hydralazine; coronary artery disease; mitral valvular rheumatic heart disease.

In a few patients hydralazine may produce a clinical picture simulating systemic lupus erythematosus including glomerulonephritis. In such patients hydralazine should be discontinued unless the benefit-to- risk determination requires continued antihypertensive therapy with this drug. Symptoms and signs usually regress when the drug is discontinued but residua have been detected many years later. Long- term treatment with steroids may be necessary (see PRECAUTIONS, Laboratory Tests ) .

Drug Interactions MAO inhibitors should be used with caution in patients receiving hydralazine. When other potent parenteral antihypertensive drugs, such as diazoxide, are used in combination with hydralazine, patients should be continuously observed for several hours for any excessive fall in blood pressure. Profound hypotensive episodes may occur when diazoxide injection and hydralazine injection are used concomitantly.

Pregnancy Teratogenic effects : Animal studies indicate that hydralazine is teratogenic in mice at 20 to 30 times the maximum daily human dose of 200 to 300 mg and possibly in rabbits at 10 to 15 times the maximum daily human dose, but that it is nonteratogenic in rats. Teratogenic effects observed were cleft palate and malformations of facial and cranial bones. There are no adequate and well-controlled studies in pregnant women.