Hydralazine is a vasodilator. It relaxes (widens) veins and arteries, which makes it easier for your heart to pump.

Isosorbide dinitrate is in a group of drugs called nitrates. Isosorbide dinitrate dilates (widens) blood vessels, making it easier for blood to flow through them and easier for the heart to pump.

Hydralazine and isosorbide dinitrate is a combination medicine used to treat heart failure.

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

Do not use hydralazine and isosorbide dinitrate if you are taking medicine to treat erectile dysfunction or pulmonary arterial hypertension (PAH). This includes sildenafil (Viagra, Revatio), avanafil (Stendra), tadalafil (Cialis, Adcirca), vardenafil (Levitra, Staxyn), and riociguat (Adempas). Serious, life-threatening side effects may occur.

You should not use this medicine if you are allergic to hydralazine, isosorbide dinitrate, isosorbide mononitrate, or nitroglycerin.

To make sure hydralazine and isosorbide dinitrate is safe for you, tell your doctor if you have:

• lupus;
• low blood pressure; or
• pulmonary arterial hypertension.

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

It is not known whether hydralazine and isosorbide dinitrate passes into breast milk or if it could harm a nursing baby. Tell your doctor if you are breast-feeding a baby.

Use Hydralazine And Isosorbide Dinitrate (Oral) exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended.

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

This medicine can cause headaches, especially when you first start using it. These headaches may gradually become less severe as you continue to use the medicine. Do not stop taking hydralazine and isosorbide dinitrate. Call your doctor before using any headache pain medication.

Call your doctor at once if you have:

• a light-headed feeling, like you might pass out;
• numbness or tingling in your hands or feet;
• joint pain or swelling;
• fever, chest pain, general ill feeling;
• fast heart rate;
• shortness of breath that is worse than usual; or
• heart attack symptoms--chest pain or pressure, pain spreading to your jaw or shoulder, nausea, sweating.

Some side effects may be more likely in older adults.

Common side effects may include:

• headache; or
• dizziness.

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.

This medicine may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert. 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.

Drinking alcohol with this medicine can cause side effects.