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BiDil Side Effects

Generic name: hydralazine / isosorbide dinitrate

Medically reviewed by Last updated on Oct 19, 2022.

Note: This document contains side effect information about hydralazine / isosorbide dinitrate. Some dosage forms listed on this page may not apply to the brand name BiDil.


Common side effects of BiDil include: dizziness, headache, and nausea. Other side effects include: hypotension, and paresthesia. Continue reading for a comprehensive list of adverse effects.

Applies to hydralazine / isosorbide dinitrate: oral tablet.

Serious side effects of BiDil

Along with its needed effects, hydralazine/isosorbide dinitrate may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking hydralazine/isosorbide dinitrate:

More common

  • Blurred vision
  • confusion
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • sweating
  • unusual tiredness or weakness

Less common

  • Fainting
  • fast, pounding, or irregular heartbeat or pulse

Incidence not known

  • Abdominal or stomach cramps or pain
  • black, tarry stools
  • bloating or swelling of the face, arms, hands, lower legs, or feet
  • chest pain or discomfort
  • dark urine
  • diarrhea
  • difficult or labored breathing
  • fever or chills
  • headache, severe and throbbing
  • joint pain
  • light-colored stools
  • lower back or side pain
  • mood or mental changes
  • muscle aches, cramps, or stiffness
  • pain in the arms or legs
  • painful or difficult urination
  • pale skin
  • shortness of breath
  • sores, ulcers, or white spots on the lips or inside the mouth
  • unusual behavior, such as disorientation to time or place, failure to recognize people, hyperactivity, or restlessness
  • unusual bruising or bleeding
  • unusual weight gain or loss
  • yellow eyes and skin

Other side effects of BiDil

Some side effects of hydralazine / isosorbide dinitrate may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Less common

  • Burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • cough
  • pain or tenderness around the eyes and cheekbones
  • stuffy or runny nose

Incidence not known

  • Change in urine color
  • continuing ringing, buzzing or other unexplained noise in the ears
  • feeling of constant movement of self or surroundings
  • feeling of warmth
  • inability to have or keep an erection
  • pinpoint red or purple spots on the skin
  • redness of the face, neck, arms and occasionally, upper chest
  • sensation of spinning
  • stomach soreness or discomfort

For Healthcare Professionals

Applies to hydralazine / isosorbide dinitrate: oral tablet.


The most common side effects were headache, dizziness, asthenia, and nausea.[Ref]

Nervous system

Very common (10% or more): Headache (50%), dizziness (32%)

Common (1% to 10%): Paresthesia

Postmarketing reports: Tinnitus, dysgeusia, hypoesthesia, migraine, syncope[Ref]


Very common (10% or more): Asthenia (14%)

Postmarketing reports: Vertigo, facial pain, chest discomfort, chest pain, peripheral edema[Ref]


Very common (10% or more): Nausea (10%)

Common (1% to 10%): Vomiting

Postmarketing reports: Abdominal discomfort, constipation[Ref]


Common (1% to 10%): Hypotension, ventricular tachycardia

Postmarketing reports: Palpitations, flushing[Ref]


Common (1% to 10%): Amblyopia

Postmarketing reports: Eyelid edema, vision blurred[Ref]


Common (1% to 10%): Sinusitis

Postmarketing reports: Dyspnea[Ref]


Postmarketing reports: Erythema, hyperhidrosis, pruritus, face swelling[Ref]


Postmarketing reports: Chromaturia, erectile dysfunction[Ref]


Postmarketing reports: Pain in extremity, myalgia[Ref]


Postmarketing reports: Pulmonary renal syndrome[Ref]


1. Product Information. BiDil (hydralazine-isosorbide dinitrate). NitroMed Inc. 2005.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Some side effects may not be reported. You may report them to the FDA.