BiDil (Hydralazine Hydrochloride; Isosorbide Dinitrate) - Oral

What Is BiDil?

BiDil (hydralazine hydrochloride and isosorbide dinitrate) is a fixed-dose combination (FDC) prescription medication made up of two drugs, hydralazine hydrochloride and isosorbide dinitrate. Hydralazine hydrochloride is an arteriolar vasodilator that relaxes and widens your body's veins and arteries to make it easier for the heart to pump blood.

Isosorbide dinitrate belongs to a class of drugs called nitrates and is specifically categorized as a nitrate vasodilator. Nitrates work to dilate blood vessels and improve blood flow.

BiDil is used to treat heart failure in certain people as an adjunct therapy (a drug used in combination with the primary treatment).

BiDil is available in an oral tablet form.

Drug Facts

Generic Name: Hydralazine hydrochloride and isosorbide dinitrate

Brand Name: BiDil

Drug Availability: Prescription

Therapeutic Classification: Antianginal

Available Generically: Yes

Controlled Substance: No

Administration Route: Oral

Active Ingredient: Hydralazine hydrochloride and isosorbide dinitrate

Dosage Form(s): Tablet

What Is BiDil Used For?

BiDil is prescribed for the treatment of heart failure as an addition to primary therapy in self-identified Black people. The treatment therapy with BiDil improves the quality of life and survival in African American people with heart failure.

How to Take BiDil

Follow the prescription label carefully and ask your healthcare provider or pharmacist about anything you do not understand. Take one tablet, three times a day with or without food or as directed by your healthcare provider. 

To avoid missing the doses, take it at the same time each day. Do not stop taking BiDil without consulting your healthcare provider. Sudden discontinuation of the drug may worsen the condition. Your healthcare provider may gradually decrease your dose to ensure you do not get any withdrawal symptoms. Do not use hydralazine and isosorbide dinitrate more or less than prescribed or for longer than recommended.


Store BiDil at room temperature away from heat, light, and moisture in the container it came in. Keep all the medication out of reach of children. To protect children from poisoning, always lock safety caps and place the medication safely out of their sight and reach after use. Do not use expired medicines.

Discard all the unneeded medications. Do not flush the medication down the toilet; throw it in the bin; or dispose of it in the drain. Instead, dispose of your unnecessary medication through a medicine take-back program. Contact your pharmacist or your local waste control department to talk about medicine take-back programs in your community.

How Long Does BiDil Take to work?

Following oral administration of BiDil, the two active metabolites reach peak plasma concentration in one hour.

What Are the Side Effects of BiDil?

This is not a complete list of side effects, and others may occur. A healthcare provider can advise you on side effects. If you experience other effects, contact your pharmacist or a healthcare provider. You may report side effects to the Food and Drug Administration (FDA) at or 800-FDA-1088.

As with all medications, BiDil can cause side effects. Tell your healthcare provider about any side effects you experience while taking this medication.

Common Side Effects

Common side effects of BiDil include:

Severe Side Effects

Call your healthcare provider right away if you have serious side effects. Call 911 if your symptoms feel life-threatening or if you think you’re having a medical emergency.

Serious side effects and their symptoms can include the following:

A severe allergic reaction to BiDil is rare. However, if you notice any symptoms of a severe allergic reaction, such as rash, itching/swelling of the face/tongue/throat, severe dizziness, or trouble breathing, get medical help right away.

Report Side Effects

BiDil may cause other side effects. Call your healthcare provider if you have any unusual problems while taking this medication.

If you experience a serious side effect, you or your healthcare provider may send a report to the FDA's MedWatch Adverse Event Reporting Program or by phone (800-332-1088).

Dosage: How Much BiDil Should I Take?

Drug Content Provided and Reviewed by IBM Micromedex®

The dose of this medicine will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of this medicine. If your dose is different, do not change it unless your doctor tells you to do so.

The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.

  • For treatment of heart failure:
    • For oral dosage form (tablets):
      • Adults—At first, one tablet three times a day. Your doctor may adjust your dose as needed. Each tablet contains 20 milligrams (mg) of isosorbide dinitrate and 37.5 mg of hydralazine.
      • Children—Use and dose must be determined by your doctor.


Due to the possible effects of this medication, there may be changes to how BiDil is used. Users should be aware of the following before taking BiDil:

Severe allergic reaction: Avoid using BiDil if you have a known allergy to it or any of its ingredients. Ask your pharmacist or healthcare provider for a complete list of the ingredients if you're unsure.

Pregnancy: ​​There are no data on BiDil use in pregnant people, and insufficient data on its ingredients (hydralazine and isosorbide dinitrate) to assess a drug-associated risk of major birth defects or miscarriage with first-trimester use. 

Available published data on BiDil use in pregnancy during the second and third trimesters have not shown negative pregnancy-related outcomes. Regardless, if you are pregnant or planning to be pregnant, consult your healthcare provider before taking BiDil.

Breastfeeding: Caution is recommended with breastfeeding as there are limited data available on its effects. Talk with your healthcare provider if you plan to breastfeed, weigh the benefits and risks of taking BiDil while nursing, and the different ways available to feed your baby.

Adults over 65: The combination of hydralazine hydrochloride and Isosorbide dinitrate may be eliminated more slowly in older adults. The therapy should be initiated at low doses because of the possibility of decreased renal and hepatic function, diseases, and accompanying use of other medications.

Missed Dose

If you missed a dose of BiDil, take it as soon as you remember. If it is nearly the time for your next dose, skip the missed dose and take the next dose at the regular time. Do not take two doses at one time to make up for the missed one.

Overdose: What Happens If I Take Too Much BiDil?

If someone has accidentally overdosed on BiDil, immediately contact the Poison Control Center. If the person feels like passing out, faints, or has difficulty breathing, call 911 right away for help. 

The overdose symptoms may include:

If not treated, complications of overdose may include lack of oxygen to the heart (myocardial ischemia), heart attack (myocardial infarction), and irregular heart rhythm (atrial fibrillation) leading to shock, coma, and death.

What Happens If I Overdose on BiDil?

If you think you or someone else may have overdosed on BiDil, call a healthcare provider or the Poison Control Center (800-222-1222).

If someone collapses or isn't breathing after taking BiDil, call 911 immediately.


Drug Content Provided and Reviewed by IBM Micromedex®

It is important that your doctor check your progress at regular visits to make sure that this medicine is working properly and to check for unwanted effects.

Do not take avanafil (Stendra®), riociguat (Adempas®), sildenafil (Viagra®), tadalafil (Cialis®), or vardenafil (Levitra®) while you are using this medicine. Using these medicines together may cause blurred vision, severe dizziness, lightheadedness, or fainting. If you are taking these medicines and you experience an angina attack, you must go to the hospital right away.

Dizziness, lightheadedness, or faintness may occur, especially when you get up quickly from a lying or sitting position. Getting up slowly may help.

Dizziness, lightheadedness, or fainting is also more likely to occur if you drink alcohol, stand for long periods of time, exercise, or if the weather is hot. While you are taking this medicine, be careful to limit the amount of alcohol you drink. Also, use extra care during exercise or hot weather or if you must stand for long periods of time.

Call your doctor right away if you have chest pain, fever, joint pain, or unusual tiredness or weakness. These may be symptoms of an autoimmune disease called systemic lupus erythematosus.

This medicine may cause nerve problems. Call your doctor right away if you have burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings.

What Are Reasons I Shouldn't Take BiDil?

BiDil is not appropriate for everyone. You should not take this medication if you are allergic to any of the inactive ingredients in BiDil.

BiDil may be used with caution in some people only if the healthcare provider determines it is safe. This includes people who are:

What Other Medications May Interact With BiDil?

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter (OTC) medicines and vitamins or supplements.

BiDil interacts with some drugs when taken together. It may change how certain medications work and can increase the risk for serious side effects. 

Drugs that may interact negatively with BiDil include:

If taking any of the above medications, talk to your healthcare provider before using BiDil. You may need to avoid the medication or use a lower dose.

What Medications Are Similar?

BiDil is a relatively unique drug, combining two drugs from two different drug classes for specific people.

Consult your healthcare provider or pharmacist if you are trying to find a suitable OTC option to treat your symptoms. There are many products with similar names and ingredients, so you'll want to ensure you pick the safest medication for you.

Frequently Asked Questions

  • What is BiDil used for?

    BiDil is prescribed for the treatment of heart failure as an addition to standard therapy in self-identified Black people.

  • How does BiDil work?

    BiDil contains two drugs, hydralazine hydrochloride and isosorbide dinitrate. These drugs are vasodilators and work by relaxing and widening blood vessels to improve blood flow to the heart.

  • What drugs should not be taken with BiDil?

    While on treatment with BiDil, do not use PDE5 inhibitors such as Viagra (sildenafil), Cialis (tadalafil), Stendra (avanafil), and Adempas (riociguat). The tandem use of these drugs can cause severe hypotension.

  • What are the side effects of BiDil?

    Some common side effects of BiDil are headache, dizziness, flushing, and nausea. If you notice any other unusual symptoms or these problems become worse, immediately contact your healthcare provider.

  • How to stop taking BiDil?

    Never stop taking any drug without consulting your healthcare provider. Abrupt discontinuation of a drug can cause problems such as withdrawal symptoms or worsening of your condition.

  • Can I drink alcohol with BiDil?

    Avoid drinking alcohol while taking BiDil as the drug can make can exaggerate existing side effects.

How Can I Stay Healthy While Taking BiDil?

BiDil is a combination drug having drugs from two different classes to improve the additional benefit in self-identified people of African descent with advanced heart failure. This subgroup has shown up a favorable response to this therapy.

Be careful while using a machine or driving unless you know how this drug affects you. Keep yourself affirmed and steady when standing up from a sitting or lying position to avoid dizziness. Keep all the appointments with your healthcare provider to get the maximum benefit from the therapy. 

Medical Disclaimer

Verywell Health's drug information is meant for educational purposes only and is not intended to replace medical advice, diagnosis, or treatment from a healthcare provider. Consult your healthcare provider before taking any new medication(s). IBM Watson Micromedex provides some of the drug content, as indicated on the page.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Food and Drug Administration. BiDil (isosorbide dinitrate and hydralazine hydrochloride) prescribing information.

  2. MedlinePlus. Hydralazine.

  3. MedlinePlus. Isosorbide.

  4. Heart and Stroke Foundation of Canada. Nitrates (nitroglycerin).

  5. Echols MR, Yancy CW. Isosorbide dinitrate-hydralazine combination therapy in African Americans with heart failure. Vasc Health Risk Manag. 2006;2(4):423-431. doi:10.2147/vhrm.2006.2.4.423

  6. Carmody MS, Anderson JR. BiDil (isosorbide dinitrate and hydralazine): a new fixed-dose combination of two older medications for the treatment of heart failure in black patients. Cardiol Rev. 2007;15(1):46-53. doi:10.1097/01.crd.0000250840.15645.fb

  7. Prescribers’ Digital Reference. Hydralazine hydrochloride/isosorbide dinitrate