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.

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not use this medicine in larger or smaller amounts or for longer than recommended.

You should not stop using hydralazine and isosorbide dinitrate suddenly. Stopping suddenly may make your condition worse.

Store at room temperature away from moisture, heat, and light.

Usual Adult Dose for Congestive Heart Failure:

Initial dose: Hydralazine 37.5 mg-Isosorbide dinitrate 20 mg orally three times a day
Maximum dose: Hydralazine 75 mg-Isosorbide dinitrate 40 mg orally three times a day

Comments:
-May titrate up every 3 to 5 days, but some patients may experience side effects and take longer to reach their maximum tolerated dose.
-May decrease as low as hydralazine 18.75 mg-isosorbide dinitrate 10 mg three times a day if intolerable side effects occur; should titrate up as soon as side effects subside.

Use: Treatment of heart failure as an adjunct to standard therapy in self-identified black patients to improve survival, prolong time to hospitalization for heart failure, and improve patient-reported functional status. Experience in patients with New York Heart Association (NYHA) class IV heart failure is limited.

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 hydralazine and isosorbide dinitrate 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.

Follow all directions on your prescription label. Your doctor may occasionally change your dose to make sure you get the best results. Do not use hydralazine and isosorbide dinitrate in larger or smaller amounts or for longer than recommended.

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

Overdose symptoms may include warmth or tingly feeling under your skin, confusion, severe dizziness, throbbing headache, fast heartbeats, and chest pain.

hydralazine and isosorbide dinitrate 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.

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

hydralazine and isosorbide dinitrate 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.

Hydralazine and isosorbide dinitrate may cause serious side effects. 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 of hydralazine and isosorbide dinitrate 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.

Other drugs may interact with hydralazine and isosorbide dinitrate, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.