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Hydralazine Side Effects

For the Consumer

Applies to hydralazine: oral tablet

Other dosage forms:

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

Major Side Effects

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

More common:
  • Arm, back, or jaw pain
  • chest pain or discomfort
  • chest tightness or heaviness
  • fast, pounding, or irregular heartbeat or pulse
  • nausea
  • shortness of breath
  • sweating
Less common:
  • Black, tarry stools
  • blindness or vision changes
  • blisters on the skin
  • blurred vision
  • burning of the face or mouth
  • burning, crawling, itching, numbness, painful, prickling, "pins and needles", or tingling feelings
  • chills
  • clumsiness or unsteadiness
  • confusion
  • cough
  • difficult or labored breathing
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • fever and sore throat
  • general feeling of discomfort or illness or weakness
  • joint pain
  • lower back or side pain
  • muscle pain
  • numbness, tingling, pain, or weakness in the hands or feet
  • painful or difficult urination
  • pale skin
  • shakiness in the legs, arms, hands, or feet
  • skin rash or itching
  • swelling of the feet or lower legs
  • swollen, painful, or tender lymph glands in the neck, armpit, or groin
  • tightness in the chest
  • trembling or shaking of the hands or feet
  • ulcers, sores, or white spots in the mouth
  • unusual bleeding or bruising
  • unusual tiredness or weakness
  • weakness in hands or feet
  • Dark urine
  • light-colored stools
  • upper right abdominal or stomach pain
  • yellow eyes and skin

If any of the following symptoms of overdose occur while taking hydralazine, get emergency help immediately:

Symptoms of overdose:
  • Feeling of warmth
  • headache
  • redness of the face, neck, arms, and occasionally, upper chest

Minor Side Effects

Some of the side effects that can occur with hydralazine 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:
  • Diarrhea
  • loss of appetite
  • weight loss
Less common:
  • Constipation
  • difficulty with moving
  • dizziness
  • feeling anxious or depressed
  • muscle cramps, pain, or stiffness
  • pain in the joints
  • rash, hives, welts, or itching
  • stuffy nose
  • watery eyes

For Healthcare Professionals

Applies to hydralazine: compounding powder, injectable solution, oral tablet


The most frequently reported side effects were palpitations and tachycardia.[Ref]


Very common (10% or more): Palpitations, tachycardia
Common (1% to 10%): Angina pectoris, flushing, hypotension
Uncommon (0.1% to 1%): Heart failure, vasculitis
Very rare (less than 0.01%): Paradoxical pressor response[Ref]


Common (1% to 10%): Nausea, vomiting, diarrhea, gastrointestinal disturbances
Very rare (less than 0.01%): Paralytic ileus
Frequency not reported: Constipation[Ref]

Nervous system

Common (1% to 10%): Headache
Uncommon (0.1% to 1%): Dizziness
Very rare (less than 0.01%): Peripheral neuritis, paresthesia, tremor, polyneuritis
Frequency not reported: Tingling, numbness[Ref]


Common (1% to 10%): Arthralgia, joint swelling, myalgia
Uncommon (0.1% to 1%): Systemic lupus erythematosus-like syndrome
Frequency not reported: Muscle cramp[Ref]


Common (1% to 10%): Anorexia[Ref]


Common (1% to 10%): Positive antinuclear factor[Ref]


Uncommon (0.1% to 1%): Nasal congestion, dyspnea, pleural pain[Ref]


Uncommon (0.1% to 1%): Anemia, leukopenia, neutropenia, thrombocytopenia
Very rare (less than 0.01%): Hemolytic anemia, leukocytosis, lymphadenopathy, pancytopenia, splenomegaly, agranulocytosis, eosinophilia
Frequency not reported: Blood dyscrasias, hemoglobin decreased, red cell count decreased[Ref]


Uncommon (0.1% to 1%): Serum creatinine increased, glomerulonephritis
Very rare (less than 0.01%): Acute renal failure[Ref]


Uncommon (0.1% to 1%): Rash, purpura, urticaria, pruritus[Ref]


Uncommon (0.1% to 1%): Jaundice, liver enlarged, abnormal liver function, hepatitis[Ref]


Uncommon (0.1% to 1%): Hypersensitivity reaction[Ref]


Uncommon (0.1% to 1%): Proteinuria, hematuria, urinary retention
Very rare (less than 0.01%): Retroperitoneal fibrosis
Frequency not reported: Urination difficult[Ref]


Uncommon (0.1% to 1%): Lacrimation increased, conjunctivitis
Very rare (less than 0.01%): Exophthalmos[Ref]


Uncommon (0.1% to 1%): Edema, fever, weight decreased, malaise
Frequency not reported: Chills[Ref]


Uncommon (0.1% to 1%): Agitation, anxiety
Very rare (less than 0.01%): Depression, hallucinations
Frequency not reported: Psychotic reactions, disorientation, anxiety[Ref]


1. "Product Information. HydrALAZINE Hydrochloride (hydrALAZINE)." Akorn Inc, Buffalo Grove, IL.

2. Cerner Multum, Inc. "Australian Product Information." O 0

3. "Product Information. Apresoline (hydralazine)." Ciba Pharmaceuticals, Summit, NJ.

4. Cerner Multum, Inc. "UK Summary of Product Characteristics." O 0

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

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.