Hydralazine is used with or without other medications to treat high blood pressure. Lowering high blood pressure helps prevent strokes, heart attacks, and kidney problems. Hydralazine is called a vasodilator. It works by relaxing blood vessels so blood can flow through the body more easily.


Take this medication by mouth with or without food, usually 2 to 4 times daily or as directed by your doctor. The dosage is based on your medical condition and response to treatment. Your doctor may start you at a low dose and gradually increase your dose. Follow your doctor's instructions carefully.

Side effects

Headache, pounding/fast heartbeat, loss of appetite, nausea, vomiting, diarrhea, or dizziness may occur as your body adjusts to the medication. If any of these effects last or get worse, tell your doctor or pharmacist promptly.

This medication may rarely cause nerve problems. Tell your doctor promptly if you experience numbness or tingling. Your doctor may recommend a vitamin B6 supplement .


Mechanism of action

Direct vasodilation of arterioles (with little effect on veins) with decreased systemic resistance. Although exact mechanism unknown, arterial vasodilation may occur via inhibition of calcium release from the sarcoplasmic reticulum and inhibition of myosin phosphorylation in arterial smooth muscle cells.

Half-Life Elimination

3 to 7 hours

Drugs: Hydralazine

WebMD: Hydralazine