Find a Doctor:   

By Medicover Hospitals / 11 Mar 2021
Home | Medicine | Hydralazine

What is Hydralazine?

  • Hydralazine, also known as Apresoline, is a medication used to treat high blood pressure and heart failure. This includes high blood pressure during pregnancy.
  • Although the precise mechanism of hydralazine is unknown, the most significant effects are on the cardiovascular system.
    1. Hydralazine Uses
    2. Hydralazine Side effects
    3. Precautions
    4. Overdose
    5. Warnings
    6. Storage
    7. Hydralazine vs Nitroglycerin
    8. Frequently Asked Questions
    9. Citations

    Hydralazine Uses:

  • This is used to treat high blood pressure, either alone or in combination with other medications. Lowering high blood pressure aids in the prevention of strokes, heart attacks, and kidney problems. It is classified as a vasodilator. It works by relaxing blood vessels, allowing blood to flow more easily through the body.
  • How to use:

    • Take this medication orally, with or without food, 2 to 4 times per day, or as directed by your doctor. The dosage is evaluated by your medical condition as well as your response to treatment. Your doctor may begin with a low dose and gradually increase it.
    • To get the benefit out of this medication, take it on a regular basis. Take it at the same times every day to help you remember. Even if you feel fine, continue to take this medication. The majority of people with high blood pressure do not feel ill. It could take several weeks before you get the full benefit of this medication.
    • Do not suddenly discontinue taking this medication without first consulting your doctor. Some conditions may worsen if the drug is abruptly discontinued. It is possible that your dose will gradually be reduced.
    • If your condition worsens, notify your doctor (for example, your routine blood pressure readings increase).

    Hydralazine Side Effects:

  • Some of the serious side effects are:
    • Flushing
    • Headache
    • Upset stomach
    • Vomiting
    • Loss of appetite
    • Diarrhea
    • Constipation
    • Eye tearing
    • Stuffy nose
    • Rash
    • Fainting
    • Joint or muscle pain
    • Fever
    • Rapid heartbeat
    • Chest pain
    • Swollen ankles or feet
    • Numbing or tingling in hands or feet


    • Tell your doctor or pharmacist if you are allergic to it or if you have any other allergies before taking it. Give detail about your medical history, especially if you have: heart problems (such as coronary artery disease, recent heart attack, rheumatic heart disease of the mitral valve), blood vessel problems, previous stroke, or kidney problems.
    • This medication may cause dizziness. Do not do the things that require alertness until you are confident that you can do it safely. Limit your intake of alcohol. This medication should be used only when prescribed by a doctor during pregnancy. Consult your doctor.
    • This medication is excreted in breast milk, but it is unlikely to harm a nursing infant. Before breastfeeding, talk to your doctor.


  • MAO inhibitors are some products that may interact with this medication (isocarboxazid, linezolid, methylene blue, moclobemide, phenelzine, procarbazine, rasagiline, safinamide, selegiline, tranylcypromine).
  • Some products contain ingredients that may increase your heart rate, blood pressure, or worsen your heart failure. Tell your pharmacist about the products you're using and how to use them safely (especially cough and cold remedies, diet supplements, or NSAIDs like ibuprofen/naproxen).
  • Missed Dose:

  • If you forget to take one of the dosages, take it as soon as you remember. Skip the missed dose and proceed with your daily schedule. To cope up with a missed dose, do not take a double dose.
  • Overdose:

  • Overdose of a drug can be accidental. If you have taken more than the prescribed tablets there is a chance of getting a harmful effect on your body’s functions.
  • Storage:

  • Exposure of medicine to heat, air, and light may cause some harmful effects. The medicine must be kept in a safe place and out of children’s reach.
  • Hydralazine vs Nitroglycerin:

    It is also known as Apresoline, is a medication used to treat high blood pressure and heart failure. Nitroglycerin, also known as glyceryl trinitrate (GTN)
    It is used to treat high blood pressure, either alone or in combination with other medications. Lowering blood pressure helps in preventing strokes, heart attacks, and kidney problems. It is a medication used for treating and preventing heart failure, hypertension, anal fissures, painful periods, and chest pain caused by decreased blood flow to the heart or recreational cocaine use.
    It works by relaxing blood vessels, allowing blood to flow more easily through the body. Nitroglycerin works by relaxing your body's smooth muscle and blood vessels.

    Frequently Asked Questions:

    Hydralazine belongs to the class of medications that are known as vasodilators. It works by relaxing blood vessels and allowing blood to flow more freely throughout the body.
    It works by relaxing blood vessels and increasing blood & oxygen supply to the heart while decreasing its workload. The hydrochlorothiazide is a thiazide diuretic, which reduces the amount of water in the body by acting on the kidneys to increase the flow of urine.
    Hydralazine is used to treat moderate to severe hypertension in combination with a beta-blocker and a diuretic. To avoid edema, a loop diuretic rather than a thiazide is required when renal function is severely impaired.
    You should not take it when you are allergic to hydralazine, or if you have coronary artery disease or rheumatic heart disease affecting the mitral valve, you should not use it.
    No, because it is not a water pill, it is not known to increase the frequency with which you urinate. It lowers blood pressure by relaxing your blood vessels.
    Although the oral tablet does not cause drowsiness, it may have other side effects.
    If you only need one dose per day, take it in the morning after breakfast. If you take more than one dose per day, the last dose should be taken no later than 6 p.m., unless otherwise directed by your doctor.
    Adults—10 milligrams (mg) four times per day at first. Your dose may be adjusted by your doctor as needed. However, the typical dose is no more than 50 mg four times per day. Children—The dose is determined by your doctor and is based on body weight.


  • Hydralazine,
  • Hydralazine dose