- High Blood Pressure Slideshow Pictures
- Take the Salt Quiz!
- Lowering Blood Pressure Exercise Tips Pictures
- What is hydralazine-oral, and how does it work (mechanism of action)?
- What brand names are available for hydralazine-oral?
- Is hydralazine-oral available as a generic drug?
- Do I need a prescription for hydralazine-oral?
- What are the uses for hydralazine-oral?
- What are the side effects of hydralazine-oral?
- What is the dosage for hydralazine-oral?
- Which drugs or supplements interact with hydralazine-oral?
- Is hydralazine-oral safe to take if I'm pregnant or breastfeeding?
- What else should I know about hydralazine-oral?
What is hydralazine-oral, and how does it work (mechanism of action)?
Hydralazine (Apresoline) is an antihypertensive medication used to treat high blood pressure. It is a peripheral arterial vasodilator and causes relaxation of blood vessels which carry blood away from the heart and towards the organs and tissues. The exact mechanism of how hydralazine causes arterial smooth muscle relaxation is not yet understood. Hydrazine affects calcium movement within blood vessels. Calcium is required for muscle contraction and therefore disturbances in calcium movement may cause smooth muscle relaxation in the blood vessels. Hydralazine is selective for arterioles (small arteries), and the overall effects of treatment include a decrease in arterial blood pressure, and peripheral vascular resistance.
In addition to treating high blood pressure, hydralazine has shown to be beneficial for the treatment of congestive heart failure (CHF). Although ACE inhibitors are preferred for the treatment of CHF, hydralazine in combination with isosorbide dinitrate (Isordil, Isordil Titradose, Dilatrate-SR) is an alternative for patients who cannot tolerate ACE inhibitors.
Hydralazine was approved by the US Food and Drug Administration (FDA) in 1952 as an antihypertensive agent. It is commonly used for the treatment of hypertension in pregnancy. Parenteral or injectable hydralazine is used to treat hypertensive emergencies (severally high blood pressure) during pregnancy.
What are the uses for hydralazine-oral?
Hydralazine is used for the treatment of essential hypertension (high blood pressure), alone or in-combination with other anti-hypertensive medications. It is also used for treating hypertensive crisis and congestive heart failure.
What are the side effects of hydralazine-oral?
Common side effects of hydralazine are:
- headache,
- anorexia,
- nausea,
- vomiting,
- diarrhea,
- palpitations,
- tachycardia (rapid heartbeat), and
- angina pectoris (chest pain).
Other less commonly reported side effects include:
- constipation,
- paralytic ileus,
- low blood pressure,
- edema,
- paradoxical pressor response,
- dyspnea (shortness of breath),
- peripheral neuritis,
- numbness,
- tingling,
- tremors,
- muscle cramps,
- psychotic reactions,
- difficulty urinating,
- blood disorders,
- hypersensitivity type reactions,
- nasal congestion,
- flushing,
- abnormal tear production (lacrimation) , and
- conjunctivitis.

QUESTION
Salt and sodium are the same. See AnswerWhat is the dosage for hydralazine-oral?
Hypertension in adult patients:
- Start treatment at a low dose and increase gradually based on individual patient response. The usual recommended starting regimen is 10 mg orally four times daily for the first 2 to 4 days, increase to 25 mg four times daily for the remainder of the first week.
- For the second and subsequent weeks, increase dosage to 50 mg four times daily (increase dose by 10-25 mg/dose gradually every 2-5 days).
- The maximum daily dose used in clinical studies is 300 mg.
Congestive heart failure:
- The initial dose for treating heart failure is 10 to 25 mg orally 3 to 4 times daily.
- The usual dose is 225 to 300 mg daily in 3 to 4 divided doses.
For pediatric hypertensive emergencies, the dose is 0.5 mg/Kg IV every 4 hours.
Which drugs or supplements interact with hydralazine-oral?
Sympathomimetics such as:
- cocaine,
- dobutamine (Dobutrex),
- dopamine (Intropin),
- norepinephrine (Levophed),
- epinephrine (Adrenalin),
- metaraminol (Aramine),
- methoxamine,
- phenylephrine, (NeoSynephrine, Neofrin)
- phenylpropanolamine,
- ephedra (Ma Huang), and
- ephedrine may decrease the effectiveness of hydralazine.
Co-administration of these agents may block the anti-hypertensive benefits of hydralazine treatment.
Is hydralazine-oral safe to take if I'm pregnant or breastfeeding?
Hydralazine should be used in pregnancy only if the potential benefit justifies the potential risk to the fetus. Hydralazine is classified as FDA pregnancy risk category C (Animal reproduction studies have shown an adverse effect on the fetus and there are no adequate and well-controlled studies in humans, but potential benefits may warrant use of the drug in pregnant women despite potential risks). It is used for treating high blood pressure during pregnancy.
Hydralazine is excreted in breast milk. Hydralazine should be used cautiously in females who are breastfeeding if treatment is necessary.
What else should I know about hydralazine-oral?
What preparations of hydralazine-oral are available?
Tablets: 10, 25, 50, 100 mg; Solution for injection: 20 mg/ml
How should I keep hydralazine-oral stored?
Tablets and injection solution may be stored at room temperature between 20 C to 25 C (68 F to 77 F).

SLIDESHOW
How to Lower Blood Pressure: Exercise and Tips See SlideshowSummary
Hydralazine (Apresoline) is a medication prescribed to treat hypertensive crisis, congestive heart failure, and high blood pressure alone or in combination with other high blood pressure medications. Side effects, drug interactions, patient safety, storage, and dosage information should be reviewed prior to taking this medication.
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High Blood Pressure (Hypertension)
High blood pressure (hypertension) is a disease in which pressure within the arteries of the body is elevated. About 75 million people in the US have hypertension (1 in 3 adults), and only half of them are able to manage it. Many people do not know that they have high blood pressure because it often has no has no warning signs or symptoms. Systolic and diastolic are the two readings in which blood pressure is measured. The American College of Cardiology released new guidelines for high blood pressure in 2017. The guidelines now state that blood normal blood pressure is 120/80 mmHg. If either one of those numbers is higher, you have high blood pressure. The American Academy of Cardiology defines high blood pressure slightly differently. The AAC considers 130/80 mm Hg. or greater (either number) stage 1 hypertension. Stage 2 hypertension is considered 140/90 mm Hg. or greater. If you have high blood pressure you are at risk of developing life threatening diseases like stroke and heart attack.REFERENCE: CDC. High Blood Pressure. Updated: Nov 13, 2017.
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Night Sweats
Night sweats are severe hot flashes that occur at night and result in a drenching sweat. The causes of night sweats in most people are not serious, like menopause in women, sleep apnea, medications, alcohol withdrawal, and thyroid problems. However, more serious diseases like cancer and HIV also can cause night sweats. Your doctor will treat your night sweats depending upon the cause. You may experience other signs and symptoms that are associated with night sweats, which depend upon the cause, but may include, shaking, and chills with a fever caused by an infection like the flu or pneumonia; unexplained weight loss due to lymphoma; women in perimenopause or menopause may also have vaginal dryness, mood swings, and hot flashes during the day; and low blood sugar in people with diabetes. Other causes of night sweats include medications like NSAIDs (aspirin, acetaminophen, ibuprofen (Motrin, Advil), and naproxen (Aleve, Naprosyn), antidepressants, sildenafil (Viagra), and abuse of prescription or illegal drugs and drug withdrawal; hormone disorders like pheochromocytoma and carcinoid syndrome; idiopathic hyperhidrosis; infections like endocarditis, AIDs, and abscesses; alcoholism and alcohol withdrawal; drug abuse, addiction, and withdrawal; and stroke. A doctor or other health care professional can treat your night sweats after the cause has been diagnosed.
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Congestive Heart Failure (CHF)
Congestive heart failure (CHF) refers to a condition in which the heart loses the ability to function properly. Heart disease, high blood pressure, diabetes, myocarditis, and cardiomyopathies are just a few potential causes of congestive heart failure. Signs and symptoms of congestive heart failure may include fatigue, breathlessness, palpitations, angina, and edema. Physical examination, patient history, blood tests, and imaging tests are used to diagnose congestive heart failure. Treatment of heart failure consists of lifestyle modification and taking medications to decrease fluid in the body and ease the strain on the heart. The prognosis of a patient with congestive heart failure depends on the stage of the heart failure and the overall condition of the individual.
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Heart Failure
Heart failure (congestive) is caused by many conditions including coronary artery disease, heart attack, cardiomyopathy, and conditions that overwork the heart. Symptoms of heart failure include congested lungs, fluid and water retention, dizziness, fatigue and weakness, and rapid or irregular heartbeats. There are two types of congestive heart failure, systolic or left-sided heart failure; and diastolic or right-sided heart failure. Treatment, prognosis, and life-expectancy for a person with congestive heart failure depends upon the stage of the disease.
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Heart Disease
Heart disease (coronary artery disease) occurs when plaque builds up in the coronary arteries, the vessels that supply blood to the heart. Heart disease can lead to heart attack. Risk factors for heart disease include: Smoking High blood pressure High cholesterol Diabetes Family history Obesity Angina, shortness of breath, and sweating are just a few symptoms that may indicate a heart attack. Treatment of heart disease involves control of heart disease risk factors through lifestyle changes, medications, and/or stenting or bypass surgery. Heart disease can be prevented by controlling heart disease risk factors.
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Things to Know About High Blood Pressure Treatment
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Heart Disease Treatment in Women
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