Skip to main content
PlainMeds

What the label lists and what reports show

Hydralazine side effects

Hydralazine's FDA label lists its adverse reactions in its own words. FAERS holds 2,614 reports naming it through July 30, 2026; the reaction reported most often, leaving out the conditions it is used for, product-use terms and outcomes, is anti-neutrophil cytoplasmic antibody positive vasculitis (420 reports).

  • Generic listed

Check it at the source: the hydralazine FDA label on DailyMed (effective April 3, 2026, Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc.); the FDA FAERS public dashboard.

What does the label list?

From the label: 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. …

Source: FDA drug label, Heritage Pharmaceuticals Inc. d/b/a Avet Pharmaceuticals Inc., effective April 3, 2026 (SPL set 669532c9-ba15-4f4b-95a8-13782deb3521), via openFDA; the full label on DailyMed

What do FAERS reports show?

2,614 reports list hydralazine among the medicines taken, each a report of something that happened, not proof the medicine caused it; 204 are coded as a death and 1,164 as a hospital stay. Counts follow how widely a medicine is used and watched, and they are not a measure of how risky it is. Of the 21 reactions below, 7 are named by the same term (in US spelling) in the label's adverse reactions, warnings or patient leaflet; a reaction the label does not name may still be there under another word, and a report does not show that the medicine caused it.

Reports received each year

The 25 most reported reactions

  • Anti-Neutrophil Cytoplasmic Antibody Positive Vasculitis420
  • Diarrhoea (named in the label)205
  • Dyspnoea (named in the label)199
  • Hypertension (a use or a product term, not a reaction)187
  • Nausea (named in the label)184
  • Off Label Use (a use or a product term, not a reaction)180
  • Drug Ineffective (a use or a product term, not a reaction)178
  • Malaise153
  • Arthralgia (named in the label)151
  • Headache (named in the label)143
  • Cough141
  • Acute Kidney Injury138
  • Abdominal Discomfort136
  • Cardiac Failure Congestive131
  • Rash (named in the label)120
  • Lupus-Like Syndrome114
  • Drug Hypersensitivity112
  • Abdominal Pain Upper111
  • Fatigue109
  • Pain101
  • Hepatic Steatosis96
  • Therapeutic Product Effect Decreased (a use or a product term, not a reaction)94
  • Dizziness (named in the label)93
  • Renal Impairment90
  • Cardiac Failure86

Source: FDA Adverse Event Reporting System (FAERS) via openFDA, reports through July 30, 2026; reactions as MedDRA preferred terms

What next?

Hydralazine: the full record
label, generics, price, shortages, recalls
Side effects hub
the most reported medicines and reactions