This page contains brief details about the drug , it's indication, dosage & administaration, mechanism of action, related brands with strength, warnings and common side effects.

Background and Date of Approval

Hydralazine belongs to the class of drugs known as vasodilators.

Mechanism of Action of undefined

Hydralazine's mechanism of action involves its direct effects on blood vessels, leading to vasodilation. When taken, it relaxes and widens the smooth muscles within the walls of arterioles (small arteries). This relaxation reduces the resistance that blood encounters as it flows through these vessels. As a result, the blood vessels dilate, allowing for increased blood flow and reducing overall systemic vascular resistance. This vasodilation leads to decreased blood pressure, which can alleviate hypertension and reduce the workload on the heart.

Uses of undefined

Hydralazine dissolves blood clots and restores blood flow in conditions such as acute ischemic stroke, acute myocardial infarction (heart attack), and pulmonary embolism.

undefined Drug administaration and Dosage available

Hydralazine is used as a tablet. Swallow with a whole glass of water. Your healthcare professional will determine the specific dosage and administration guidelines based on your condition and needs.

Warnings, Precautions and Side Effects of undefined


Hydralazine can cause a significant drop in blood pressure, which may lead to symptoms like dizziness, lightheadedness, and fainting. It has been associated with a lupus-like syndrome, which can cause joint pain, fever, skin rashes, and other autoimmune-like symptoms. This medication can sometimes cause fluid retention, leading to swelling in the legs, ankles, or feet. It  can have effects on the heart, including increasing the heart rate and potentially causing arrhythmias (irregular heartbeats). Rarely, hydralazine has been linked to peripheral neuropathy, a condition affecting the nerves outside the brain and spinal cord. This medication might worsen certain types of glaucoma due to its potential to increase intraocular pressure


Exercise caution with hydralazine due to potential blood pressure drops causing dizziness, monitor lupus-like symptoms, consult for heart/liver/kidney conditions, limit alcohol intake, seek medical advice if pregnant/breastfeeding, avoid tasks needing alertness if experiencing drowsiness, and maintain open communication with a healthcare provider.

Side Effects

Common side effects of hydralazine include headache, dizziness, flushing (reddening of the skin), rapid heartbeat, and nausea. More serious side effects may include lupus-like symptoms such as joint pain and skin rashes, severe chest pain, a significant drop in blood pressure leading to lightheadedness, and potential allergic reactions marked by swelling of the face, lips, or throat.

Word Of Advice

Be cautious of its potential to lower blood pressure, leading to dizziness and fainting; rise slowly from positions to avoid sudden drops in blood pressure. Refrain from alcohol consumption while using hydralazine to prevent intensifying side effects. Those with autoimmune disorders should monitor for lupus-like symptoms. Individuals with heart, liver, or kidney conditions should consult their healthcare provider for proper monitoring and potential dosage adjustments.  may influence blood glucose levels in diabetes patients, requiring careful monitoring. Pregnant, breastfeeding, or planning individuals should consult their healthcare provider before use. Be mindful of potential drowsiness, dizziness, and impaired coordination, avoiding tasks requiring full alertness. Regularly assess how your body responds to it and promptly communicate any concerns to your healthcare provider.

Frequently Asked Question


  1. KD Tripathi, Essentials of Medical Pharmacology, Antihypertensive drugs, 7th edition, 2013, 566.
  2. Amdipharm UK Limited, Electronic medicines compendium (emc), [Revised on July 2019] [ Accessed on 21st March 2022],


The drug information on this page is not a substitute for medical advice, it is meant for educational purposes only. For further details, consult your doctor about your medical condition to know if you can receive this treatment.