How BiDil works

Studies have shown that African Americans may be more likely to have problems with their blood vessels being able to relax. This narrows the blood vessels and makes it harder for blood to get through. Your blood vessel could look like a small pipe—there’s not a lot of space for the blood to go through.1,2

Vasoconstriction in HF

Some researchers suggest that this may have something to do with the amount of nitric oxide (NO) available. NO helps the blood vessels—including the ones in your heart—relax so more blood can flow through. When blood vessels stay narrow, it can interfere with the heart's ability to pump blood as well as it should.2

Researchers think that the 2 medicines in BiDil help to overcome the lack of NO to help the blood vessels relax. This relaxes the blood vessels, and lets blood flow through more easily.2

By helping the blood vessels in your body relax and widen, BiDil helps your heart pump blood better. This may improve blood flow and help oxygen and other nutrients reach your organs more efficiently.

Such a young-at-heart outlook

Heart failure made him old before his time

Information for Patients about BiDil® (isosorbide dinitrate/hydralazine HCl)

BiDil is approved for use with other heart medicines to treat heart failure in black patients to improve survival, improve heart failure symptoms, and help patients stay out of the hospital longer. There is little experience in patients with heart failure who experience significant symptoms while at rest. Most patients in the clinical study of BiDil also received other heart failure medicines.


Tell your doctor about any allergies you have, especially if you're sensitive to nitrates, such as nitroglycerin tablets or isosorbide dinitrate (Isordil®). BiDil has a nitrate component, so you need to let your doctor know.

Tell your doctor if you're taking any erectile dysfunction or pulmonary hypertension drugs like Viagra® or Revatio(sildenafil), Levitra® (vardenafil) or Cialis® (tadalafil).


Also tell your doctor if you are taking any medication to decrease blood pressure because when taken with BiDil, blood pressure may become too low.

It is possible you'll get headaches, especially at first, but they often lessen over time. Keep your doctor posted on your headache progress; he or she may want to adjust your dosage.

If you experience dizziness, call your doctor. Please make sure to tell your doctor about any of the signs or symptoms mentioned below or about any unusual events that worry you.

Drinking less fluids than your doctor recommends or losing fluid due to diarrhea, sweating, or vomiting may cause low blood pressure, lightheadedness, or fainting. If fainting occurs, stop taking BiDil and contact your doctor immediately.

Lightheadedness may occur when standing, especially after sitting or lying down.

If you experience any achy and/or swollen joints, unexplained fever for more than a few days, skin rashes, chest pain, prolonged weakness or fatigue (even after a good night's sleep), or any other unexplained signs or symptoms, make sure to tell your doctor as they may be signs of a serious medical condition.

You may also experience rapid heartbeat that could lead to chest pain or aggravate chest pain, or numbness or tingling in the hands or feet.


Headache and dizziness were the most frequent side effects experienced in studies with BiDil.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit or call 1-800-FDA-1088.

Please click here to see full Prescribing Information for BiDil. This information does not take the place of talking with your healthcare provider about your condition or your treatment. Ask your doctor if BiDil may be right for you.

References: 1. Sharma A, Colvin-Adams M, Yancy CW. Heart failure in African-Americans: disparities can be overcome. Cleve Clin J Med. 2014;81(5):301-311. 2. Yancy CW. Heart failure in African-Americans. US Cardiol. 2006;2005:2(1):196-200.