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Generic name: hydralazine (hye DRAL a zeen)
Brand name: Apresoline
Drug class: Vasodilators

Medically reviewed by on Dec 31, 2020. Written by Cerner Multum.

What is Apresoline?

Apresoline 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.

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

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


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

Before taking this medicine

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

  • coronary artery disease; or

  • rheumatic heart disease affecting the mitral valve.

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

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.

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

How should I take Apresoline?

Follow all directions on your prescription label. Do not take Apresoline 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.

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What happens if I miss a dose?

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.

What happens if I overdose?

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.

What should I avoid while taking Apresoline?

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.

Apresoline side effects

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

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 may include:

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.

What other drugs will affect Apresoline?

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

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.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.