The following information comes from DailyMed, an FDA label information provider.
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 (but even these can be rare)
Headache, anorexia, nausea, vomiting, diarrhea, palpitations, tachycardia, angina pectoris
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
- Hematologic: blood dyscrasias, consisting of reduction in hemoglobin and red cell count, leukopenia, agranulocytosis, purpura; lymphadenopathy; splenomegaly.
- Hypersensitivity Reactions: rash, urticaria, pruritus, fever, chills, arthralgia, eosinophilia, and rarely, hepatitis.
- Other: nasal congestion, flushing, lacrimation, conjunctivitis.