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Overview: Isosorbide dinitrate/hydralazine is a tablet taken for heart failure. It helps with heart failure by increasing oxygen and blood flow to the heart and lowering blood pressure. Common side effects include headache, dizziness, and low blood pressure. Serious side effects are rare but can include tingling, numbness, or weakness in your arms, hands, legs, or feet.

Uses

What is isosorbide dinitrate/hydralazine used for?

Isosorbide dinitrate/hydralazine is commonly used to treat heart failure.

Isosorbide dinitrate/hydralazine may also be used for other conditions as determined by your healthcare provider.

How does isosorbide dinitrate/hydralazine work (mechanism of action)?

Isosorbide dinitrate relaxes the blood vessels and increases oxygen and blood supply to the heart. Hydralazine helps to relax blood vessels in your body. This allows blood to flow more easily through the vessels, which lowers blood pressure. Together these may make it easier for your heart to pump.

How is isosorbide dinitrate/hydralazine supplied (dosage forms)?

Brand and other names

  • BiDil

Dosage forms and strengths

  • 20 mg/37.5 mg oral tablets.

How should I store isosorbide dinitrate/hydralazine?

Isosorbide dinitrate/hydralazine should be stored at room temperature, between 68 F to 77 F (20 C to 25 C). It can be exposed to temperatures between 59 F to 86 F (15 C to 30 C) for shorter periods of time, such as when transporting it. Store tightly closed in a cool, dry place. Protect from light. 

Side Effects

What are the most common side effects of isosorbide dinitrate/hydralazine?

The most common side effects of isosorbide dinitrate/hydralazine are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Headache
  • Dizziness
  • Feeling unusually weak or tired
  • Nausea
  • Low blood pressure (see below)
  • Fast heartbeat 

There may be other side effects of isosorbide dinitrate/hydralazine that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of isosorbide dinitrate/hydralazine?

While less common, the most serious side effects of isosorbide dinitrate/hydralazine are described below, along with what to do if they happen.

Low Blood Pressure (Hypotension). Isosorbide dinitrate/hydralazine may cause low blood pressure. Low blood pressure is more likely to occur if you have excessive sweating or persistent or severe vomiting or diarrhea. If you feel faint or dizzy, lie down. Stop taking isosorbide dinitrate/hydralazine and tell your healthcare provider right away if you have any of the following symptoms of low blood pressure.

  • Dizziness, feeling lightheaded, or fainting
  • Confusion
  • Feeling weak or tired

Immune System Reactions. Isosorbide dinitrate/hydralazine can cause inflammation of your liver, blood vessels, or lymph vessels and cause symptoms that look like a condition called lupus. Stop taking isosorbide dinitrate/hydralazine and call your healthcare provider right away if you develop any of the following symptoms.

  • Rash
  • Chest pain
  • Joint pain
  • Fever
  • Weakness or unusual tiredness

Chest Pain. Isosorbide dinitrate/hydralazine may cause chest pain, which can be a symptom of a heart attack. The risk of chest pain is increased in people with existing heart disease. Do not take isosorbide dinitrate/hydralazine if you have had a recent heart attack without talking to your healthcare provider. Get emergency help if you have any of the following symptoms of a heart attack.

  • Chest pain or pressure
  • Fast or abnormal heartbeat
  • Trouble breathing
  • Pain in your back, jaw, throat, or arm
  • Sweating, upset stomach, vomiting, or dizziness

Nerve Problems. Nerves are the fibers that carry sensations from your body to the brain. Damage to these nerves, called peripheral neuropathy, can happen in people who are taking isosorbide dinitrate/hydralazine. Stop taking isosorbide dinitrate/hydralazine and call your healthcare provider if you develop pain, burning, tingling, numbness, or weakness in your arms, hands, legs, or feet.

Severe Allergic Reactions. Isosorbide dinitrate/hydralazine may cause allergic reactions, which can be serious. Stop taking isosorbide dinitrate/hydralazine and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded, or fainting
  • Stomach cramps
  • Joint pain

Warnings & Precautions

Who should not use isosorbide dinitrate/hydralazine?

Allergies to Ingredients. People who are allergic to any of the following should not take isosorbide dinitrate/hydralazine.

  • BiDil
  • Isosorbide dinitrate
  • Hydralazine
  • Any other medicine known as a nitrate
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific isosorbide dinitrate/hydralazine products they stock.

Drug Interactions. Isosorbide dinitrate/hydralazine should not be taken while you are using certain other medicines. Before taking isosorbide dinitrate/hydralazine, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

What should I know about isosorbide dinitrate/hydralazine before using it?

Do not take isosorbide dinitrate/hydralazine unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share isosorbide dinitrate/hydralazine with other people, even if they have the same condition as you. It may harm them.

Keep isosorbide dinitrate/hydralazine out of the reach of children.

When taking isosorbide dinitrate/hydralazine, you may feel lightheaded when standing up, especially after getting up from lying down or sitting. Be sure to rise slowly to avoid dizziness or lightheadedness.

Isosorbide dinitrate/hydralazine can affect your alertness or coordination. Do not drive or do other activities that require alertness or coordination until you know how isosorbide dinitrate/hydralazine affects you.

People who are 65 or older can be at greater risk for some side effects from isosorbide dinitrate/hydralazine. Talk to your healthcare provider about your risks if you are in this age group.

Headaches are a common side effect with isosorbide dinitrate/hydralazine. Headaches often go away over time. If headaches continue, do not adjust your dose or stop taking isosorbide dinitrate/hydralazine. Ask your healthcare provider about how to handle this. 

What should I tell my healthcare provider before using isosorbide dinitrate/hydralazine?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if isosorbide dinitrate/hydralazine is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

  • Heart problems, such as hypertrophic cardiomyopathy
  • Liver problems, such as cirrhosis
  • Nerve pain
  • At risk for dehydration, such as with persistent or severe vomiting or diarrhea

Pregnancy. It is not known if or how isosorbide dinitrate/hydralazine could affect pregnancy or harm an unborn baby. Tell your healthcare provider if you are or plan to become pregnant.

Breastfeeding. It is not known if isosorbide dinitrate/hydralazine passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should take isosorbide dinitrate/hydralazine while breastfeeding.

Interactions

Does isosorbide dinitrate/hydralazine interact with foods or drinks?

There are no known interactions between isosorbide dinitrate/hydralazine and foods or drinks.

The risk of dizziness and low blood pressure may be increased if you drink alcohol while taking isosorbide dinitrate/hydralazine.

Does isosorbide dinitrate/hydralazine interact with other medicines (drug interactions)?

Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking isosorbide dinitrate/hydralazine.

  • A phosphodiesterase-5 (PDE-5) inhibitor, such as avanafil (Stendra), sildenafil (Viagra, Revatio, and others), tadalafil (Cialis and others), or vardenafil (Levitra, Staxyn), which is a medicine used for erectile dysfunction or pulmonary arterial hypertension (PAH)
  • Riociguat (Adempas), which is a medicine used for pulmonary arterial hypertension (PAH)
  • A medicine for high blood pressure

This may not be a complete list of medicines that can interact with isosorbide dinitrate/hydralazine. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much isosorbide dinitrate/hydralazine?

If you or someone else has used too much isosorbide dinitrate/hydralazine, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of isosorbide dinitrate/hydralazine?

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.