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Adverse reactions are usually reversible upon reduction of dosage or discontinuation of hydralazine HCI and hydrochlorothiazide. Whenever adverse reactions are moderate or severe, it may be necessary to discontinue the drug.

Hydralazine

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, and 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. Hematologic: Blood dyscrasias, consisting of reduction in hemoglobin and red cell count, leukopenia, agranulocytosis, purpura, lymphadenopathy, splenomegaly. Hypersensitive Reactions: Rash, urticaria, pruritus, fever, chills, arthralgia, eosinophilia, and rarely, hepatitis. Other: Nasal congestion, flushing, lacrimation, and conjunctivitis.

Hydrochlorothiazide

The following adverse reactions have been observed but there has not been enough systematic collection of data to support an estimate of their frequency. Consequently the reactions are categorized by organ systems and are listed in decreasing order of severity and not frequency.

Digestive: Pancreatitis, jaundice (intrahepatic cholestatic), sialadenitis, vomiting, diarrhea, cramping, nausea, gastric irritation, constipation, anorexia. Cardiovascular: Orthostatic hypotension (may be potentiated by alcohol, barbiturates, or narcotics). Neurologic: Vertigo, dizziness, transient blurred vision, headache, paresthesia, xanthopsia, weakness, and restlessness. Musculoskeletal: Muscle spasm. Hematologic: Aplastic anemia, agranulocytosis, leukopenia, and thrombocytopenia. Metabolic: Hyperglycemia, glycosuria, and hyperuricemia. Hypersensitive Reactions: Necrotizing angitis, Stevens-Johnson syndrome, respiratory distress including pneumonitis and pulmonary edema, purpura, urticaria, rash, photosensitivity.