Medicines & Supplements A to Z > Hydralazine


Last updated on July 3, 2019.

Overview   |   Dosage   |   Side Effects   |   Where To Buy  

GENERIC NAME: Hydralazine



What is Hydralazine for?

Hydralazine is a vasodilator that can relax the blood vessels in your heart and hence increase the blood and oxygen supply to your heart. It can be used to treat high blood pressure and chronic heart failure. 

How to use it?

Hydralazine can be taken by mouth as tablets. 

If you are using it for high blood pressure, the usual starting dose is 10 mg four times  daily.

If you are using it for chronic heart failure, you should take Hydralazine with a long-acting nitrate and start with 25 mg 3-4 times daily. 

Hydralazine doses are gradually  increased based on your responses. The usual maintenance dose is 50-75 mg 4 times daily.

What are the side effects of Hydralazine?

Common side effects of Hydralazine include angina, swelling in arms and legs (oedema), diarrhoea, dizziness, flushing, gastrointestinal disorders, headache, low blood pressure, joint disorders, muscle pain, nasal congestion, nausea and vomiting, palpitations, and fast heart beats.

Where to buy Hydralazine in Hong Kong?

In Hong Kong, Hydralazine is a prescription only medicine, and requires a prescription from a doctor to be purchased in a pharmacy. It can also be obtained from doctors. To find a pharmacy near you, refer to the list of pharmacies (“Authorized Sellers of Poisons”) from the Hong Kong Department of Health.

For more information about drug names and ingredients, you can visit Hong Kong’s Drug Office at

For detailed information about the use of Hydralazine in children, pregnancy and breastfeeding, and for questions about drug interactions, please check with your pharmacist or doctor.

Disclaimer: our goal is to provide you with the most relevant drug information and common dosage for Hong Kong. This information does not constitute medical advice. For specific treatment recommendations and advice, always discuss with your doctor or pharmacist, and follow the instructions included with your specific medicine.