Medicine
Fact-checked

At WiseGEEK, we're committed to delivering accurate, trustworthy information. Our expert-authored content is rigorously fact-checked and sourced from credible authorities. Discover how we uphold the highest standards in providing you with reliable knowledge.

Learn more...

What is Hydralazine?

D. Jeffress
D. Jeffress

Hydralazine is a high-strength prescription drug that is used to treat severe high blood pressure. It may be given to patients who are at risk of heart attacks due to high blood pressure as well as patients recovering from past cardiac failure. Hydralazine is highly effective in most cases, though it can cause potentially serious side effects and secondary health problems. Most doctors prefer to try other less potent drugs before prescribing hydralazine.

High blood pressure, or hypertension, can be caused by a number of different factors. Possible causes include obesity, diabetes, high cholesterol, blood clots, and congenital heart or blood vessel defects. Depending on the underlying cause of hypertension, a patient may need to take other medications in combination with hydralazine to combat symptoms. Hydralazine promotes better blood flow by relaxing the smooth muscle that surrounds arteries in the body. Arterial walls widen when they are relaxed, allowing more blood to flow through at a regulated rate.

A medical professional checks a man's blood pressure. Hydralazine may be prescribed to treat severe high blood pressure.
A medical professional checks a man's blood pressure. Hydralazine may be prescribed to treat severe high blood pressure.

Exact dosage amounts are calculated based on a patient's specific condition, underlying health problems, and age. Most adult patients, however, are given 10 milligram tablets four times a day at the beginning of treatment. A doctor can gradually increase dosage amounts to up to 50 milligrams four times a day depending on the patient's response. Physicians try to find the lowest effective dose to limit the risk of adverse reactions. Hydralazine is designed to be taken every day indefinitely, even if acute symptoms improve, to help prevent new complications from developing.

Hives may be an indication of a medication allergy.
Hives may be an indication of a medication allergy.

The risk of side effects when taking hydralazine is relatively high compared with many other hypertension drugs. A person may experience headaches, dizziness, lightheadedness, and nausea shortly after taking a dose. Digestive issues such as diarrhea and vomiting are less common but possible. The medication also may increase heart rate, which can lead to shortness of breath, fatigue, and weakness. Rarely, fever, hot flashes, skin hives, and significant breathing difficulties can develop if a person has an allergic response to the drug.

Most side effects and health complications can be avoided when patients follow their doctors' instructions about medication use and lifestyle adjustments. Doctors usually recommend that people check their blood pressure at home at least once daily during treatment to make sure it is stable. Dietary restrictions, such as limiting caffeine, alcohol, salt, and fatty foods, can also help prevent future heart problems. In addition, patients are usually instructed to exercise regularly and attend scheduled appointments to track changes in health.

Discuss this Article

Post your comments
Login:
Forgot password?
Register:
    • A medical professional checks a man's blood pressure. Hydralazine may be prescribed to treat severe high blood pressure.
      By: Rob
      A medical professional checks a man's blood pressure. Hydralazine may be prescribed to treat severe high blood pressure.
    • Hives may be an indication of a medication allergy.
      By: Jürgen Fälchle
      Hives may be an indication of a medication allergy.