Hydralazine Hydrochloride

INDICATIONS AND USAGE Essential hypertension, alone or as an adjunct.

ADVERSE REACTIONS Adverse reactions with hydralazine are usually reversible when dosage is reduced. However, in some cases it may be necessary to discontinue the drug. The following adverse reactions have been observed, but there has not been enough systematic collection of data to support an estimate of their frequency. Common headache, anorexia, nausea, vomiting, diarrhea, palpitations, tachycardia, angina pectoris. Less Frequent Digestive constipation, paralytic ileus. Cardiovascular hypotension, paradoxical pressor response, edema. Respiratory dyspnea. Neurologic peripheral neuritis, evidenced by paresthesia, numbness, and tingling, dizziness; tremors; muscle cramps; psychotic reactions characterized by depression, disorientation, or anxiety. Genitourinary difficulty in urination.

Pregnancy Teratogenic Effects Pregnancy Category C 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.

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