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Hydralazine / isosorbide dinitrate Side Effects

Not all side effects for hydralazine / isosorbide dinitrate may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to hydralazine / isosorbide dinitrate: oral tablet

In addition to its needed effects, some unwanted effects may be caused by hydralazine / isosorbide dinitrate. In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when 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

Some of the side effects that can occur with hydralazine / isosorbide dinitrate may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common
  • Constipation
  • headache
  • nausea or vomiting
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, Lexington, MA.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.