Hydralazine is a vasodilator that works by relaxing the muscles in your blood vessels to help them dilate (widen). This lowers blood pressure and allows blood to flow more easily through your veins and arteries.

Hydralazine is used to treat high blood pressure (hypertension).

Hydralazine may also be used for purposes not listed in this medication guide.

You should not use hydralazine if you have coronary artery disease, or rheumatic heart disease affecting the mitral valve.

Hydralazine comes as a tablet to take by mouth. It usually is taken two to four a day. Take hydralazine at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take hydralazine exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

Hydralazine controls high blood pressure but does not cure it. Continue to take hydralazine even if you feel well. Do not stop taking hydralazine without talking to your doctor.

Follow all directions on your prescription label. Do not take hydralazine in larger or smaller amounts or for longer than recommended.

Your blood pressure will need to be checked often. You may also need frequent blood tests.

Keep using this medicine as directed, even if you feel well. High blood pressure often has no symptoms. You may need to use blood pressure medicine for the rest of your life.

Store at room temperature away from moisture and heat.

You should not use hydralazine if you are allergic to it, or if you have:

• coronary artery disease; or

• rheumatic heart disease affecting the mitral valve.

To make sure hydralazine is safe for you, tell your doctor if you have ever had:

• kidney disease;

• systemic lupus erythematosus;

• angina (chest pain); or

• a stroke.

It is not known whether this medicine will harm an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant.

Hydralazine can pass into breast milk, but effects on the nursing baby are not known. Tell your doctor if you are breast-feeding.

Hydralazine is not approved for use by anyone younger than 18 years old.

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Overdose symptoms may include rapid heartbeats, warmth or tingling under your skin, chest pain, or fainting.

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store at room temperature and away from excess heat and moisture (not in the bathroom).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Take hydralazine with meals or a snack.

Your doctor may prescribe a low-salt or low-sodium diet. Follow these directions carefully.

Avoid getting up too fast from a sitting or lying position, or you may feel dizzy. Get up slowly and steady yourself to prevent a fall.

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Hydralazine may cause serious side effects. Call your doctor at once if you have:

• chest pain or pressure, pain spreading to your jaw or shoulder;

• fast or pounding heartbeats;

• a light-headed feeling, like you might pass out;

• numbness, tingling, or burning pain in your hands or feet;

• painful or difficult urination;

• little or no urination; or

• lupus-like syndrome--joint pain or swelling with fever, swollen glands, muscle aches, chest pain, vomiting, unusual thoughts or behavior, and patchy skin color.

Common side effects of hydralazine may include:

• chest pain, fast heart rate;

• headache; or

• nausea, vomiting, diarrhea, loss of appetite.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Tell your doctor about all your current medicines and any you start or stop using, especially:

• diazoxide (an injectable blood pressure medication); or

• an MAO inhibitor--isocarboxazid, linezolid, methylene blue injection, phenelzine, rasagiline, selegiline, tranylcypromine, and others.

This list is not complete. Other drugs may interact with hydralazine, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed in this medication guide.

Keep all appointments with your doctor and the laboratory. Your blood pressure should be checked regularly to determine your response to hydralazine.

Your doctor may ask you to check your blood pressure daily. Ask your doctor or pharmacist to teach you how.

Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

• Apresazide® (containing Hydralazine, Hydrochlorothiazide)
• Apresoline-Esidrix® (containing Hydralazine, Hydrochlorothiazide)
• BiDil® (containing Hydralazine, Isosorbide Dinitrate)
• Dralserp® (containing Hydralazine, Reserpine)
• Hydra-Zide® (containing Hydralazine, Hydrochlorothiazide)
• Hydrap-ES® (containing Hydralazine, Hydrochlorothiazide, Reserpine)
• Marpres® (containing Hydralazine, Hydrochlorothiazide, Reserpine)
• Ser-Ap-Es® (containing Hydralazine, Hydrochlorothiazide, Reserpine)
• Serathide® (containing Hydralazine, Hydrochlorothiazide, Reserpine)
• Serpazide® (containing Hydralazine, Hydrochlorothiazide, Reserpine)
• Serpex® (containing Hydralazine, Hydrochlorothiazide, Reserpine)
• Unipres® (containing Hydralazine, Hydrochlorothiazide, Reserpine)