Hydralazine Uses, Dosage, How to Take, Side Effects and Precautions

Hydralazine is an antihypertensive medication used to treat high blood pressure. It is a peripheral arterial vasodilator and causes relaxation of blood vessels which carry blood away from the heart and towards the organs. Hydrazine affects calcium movement within blood vessels. Calcium is required for muscle contraction and therefore disturbances in calcium movement may cause smooth muscle relaxation in the blood vessels.

Hydralazine dosing information:

  • Usual adult dose for Hypertension: Initial dose: 10 mg orally 4 times a day for the first 2 to 4 days; increase to 25 mg orally 4 times a day for the balance of the first week. Week 2 and subsequent weeks: 50 mg orally 4 times a day
  • Usual adult dose for Hypertensive emergency: 20 to 40 mg IM or rapid IV bolus; repeat as needed
  • Usual pediatric dose for Hypertension: Oral: Initial dose: 0.75 mg/kg/day in 4 divided doses. May increase gradually over 3 to 4 weeks to a maximum of 7.5 mg/kg/day or 200 mg/day
  • Usual pediatric dose for Hypertensive emergency: Parenteral: 1.7 to 3.5 mg/kg/day IM or IV in 4 to 6 divided doses