Hydralazine Side Effects

Medically reviewed by Drugs.com. Last updated on Jul 20, 2024.

Applies to hydralazine: oral tablet.

Other dosage forms:

• injection solution

Serious side effects of hydralazine

Along with its needed effects, hydralazine 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:

More common side effects

• 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 side effects

• 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

Rare side effects

• dark urine
• light-colored stools
• upper right abdominal or stomach pain
• yellow eyes and skin

Get emergency help immediately if any of the following symptoms of overdose occur while taking hydralazine:

Symptoms of overdose

• feeling of warmth
• headache
• redness of the face, neck, arms, and occasionally, upper chest

Other side effects of hydralazine

Some side effects of hydralazine 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 side effects

• diarrhea
• loss of appetite
• weight loss

Less common side effects

• 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.

General adverse events

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

Cardiovascular

• 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]

Gastrointestinal

• 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]

Musculoskeletal

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

Metabolic

• Common (1% to 10%): Anorexia^[Ref]

Immunologic

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

Respiratory

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

Hematologic

• 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]

Renal

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

Dermatologic

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

Hepatic

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

Hypersensitivity

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

Genitourinary

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

Ocular

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

Other

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

Psychiatric

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

Further information

Hydralazine side effects can vary depending on the individual. 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.

Medical Disclaimer