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Terms Of Use


Brand Name(s) : Apresoline
Side Effects


Hydralazine should be used with caution in:

It should not be used in:

  • women in the first and second trimesters of pregnancy, those who are allergic (hypersensitive) to hydralazine or dihydralazine or any of the products in the preparation, patients with systemic lupus erythematosus (SLE) and related diseases, patients with severe tachycardia (fast heart rate) or heart failure due to an overactive thyroid or high blood pressure in the lungs, patients with heart insufficiency due to an obstruction (e.g. in the presence of aortic or mitral stenosis or constrictive pericarditis), patients with acute porphyria, patients who have recently had a heart attack and their condition is not yet stable, or patients taking alcohol.

Also see list of precautions and interactions


Store below 25°C in the original container.


What is it used for?

  • Hydralazine is used to lower high blood pressure (hypertension).
  • It is a smooth muscle relaxant, which means it works by relaxing muscles in the large blood vessels, allowing blood to flow more freely.
  • In general this drug is used in combination with another drug (typically a beta-blocker or diuretic [water tablet]) to treat hypertension and heart failure.
  • Benefits of being on this drug include the reduction of blood pressure and prolonging patients' life in those with heart failure and reducing the likelihood of heart or circulatory problems.

Listed below are the typical uses of hydralazine:

  • Moderate hypertension
  • Severe hypertension
  • Heart failure

Your doctor may prescribe this medicine in an emergency situation to treat a condition not on the above list. Such conditions are listed below:


How often do I take it?

  • Take these tablets as instructed by your doctor - followed by a glass of water.
  • Use this medication regularly in order to get the most benefit from it.
  • Remember to use it at the same time each day - unless specifically told not to by your doctor.
  • It may take some time before the full benefit of this drug takes effect.
  • Certain medical conditions may require different dosage instructions as directed by your doctor.

What dose?

  • Dosage is based on your age, gender, medical condition, response to therapy, and use of certain interacting medicines.

Do I need to avoid anything?

  • Hydralazine may initially cause drowsiness, so avoid driving or operating machinery if this is the case. It is not advised to drink alcohol whilst taking hydralazine. Consult your doctor or pharmacist for more details.

When can I stop?

  • It is important to continue taking this medication even if you feel well, unless your doctor tells you to stop.


  • Fast heartbeat
  • Racing heart
  • Flushing
  • Low blood pressure
  • Fluid retention
  • Headache
  • Dizziness
  • Loss of appetite
  • Nausea
  • Vomiting
  • Stuffy nose
  • Stomach and intestinal disturbances
  • Systemic lupus erythematosus-like syndrome in women after long-term therapy


If any of these persist or you consider them severe then inform your doctor.

Tell your doctor immediately if you develop any of the following symptoms:

Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.

A serious allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of a serious allergic reaction include: rash, itching/swelling (especially of the face/tongue/throat), dizziness, trouble breathing.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.

The Yellow Card Scheme allows you to report suspected side effects from any type of medicine (which includes vaccines, herbals and over the counter medicines) that you are taking. It is run by the medicines safety watchdog called the Medicines and Healthcare products Regulatory agency (MHRA). Please report any suspected side effect on the Yellow Card Scheme website.


Before taking hydralazine, tell your doctor or pharmacist if you are allergic to it; or to other smooth muscle relaxants; or if you have any other allergies.

This medication should not be used if you have certain medical conditions. Before using this medicine, consult your doctor or pharmacist in case of: systemic lupus erythematosus (SLE) and related diseases, severe tachycardia (fast heart rate) or heart failure due to an overactive thyroid or high blood pressure in the lungs, patients with heart insufficiency due to an obstruction (e.g. in the presence of disease of the valves or sac that surrounds the heart), acute porphyria, a recent heart attack.

Before using this medication tell your doctor or pharmacist your medical history, especially any of the following: coronary artery disease, liver and kidney problems, cerebrovascular disease (damaged or diseased blood vessels in the brain).

Before having surgery, tell your doctor or dentist that you are taking this medication.

Does alcohol intake affect this drug?

  • Yes. Avoid alcohol whilst taking this drug.

The elderly: hydralazine can be used in the elderly.

Pregnancy and breastfeeding - please ensure you read the detailed information below


First trimester
Use of hydralazine should be avoided.

Second trimester
Use of hydralazine should be avoided.

Third trimester
The drug may be used if there is no safer alternative or if the disease being treated carries serious risks for the mother or child e.g. pre-eclampsia and/or eclampsia.

It is sensible to limit use of medication during pregnancy whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.

If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.


Hydralazine is suitable to take if you are breastfeeding. However, the manufacturer recommends that the breast-fed infant should be observed regularly for possible adverse effects.

It is sensible to limit use of medication during breastfeeding whenever possible. However, your doctor may decide that the benefits outweigh the risks in individual circumstances and after a careful assessment of your specific health situation.

If you have any doubts or concerns you are advised to discuss the medicine with your doctor or pharmacist.


Your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with them first.

This drug should not be used with the following medication because very serious, possibly fatal interactions may occur:

  • None known.

Before using this medication, tell your doctor or pharmacist of all prescription and non-prescription/herbal products you may use, especially of:

  • Anaesthetics
  • Antihypertensive medicines (medicines for high blood pressure, such as beta-blockers)
  • Central Nervous System depressants (medicines that slow down the nervous system, such as codeine)
  • Monoamine Oxidase Inhibitors or MAOIs (medicines for depression such as phenelzine)
  • Sympathomimetics (medicines for heart problems, such as ephedrine)
  • Tranquillisers (medicines for anxiety, such as chlorpromazine), Tricyclic antidepressants (medicines for depression, such as amitriptyline)
  • Baclofen
  • Tizanidine
  • Levodopa
  • Nitrates (such as glyceryl trinitrate)
  • Non-steroidal anti-inflammatory medicines (NSAIDs, such as ibuprofen)
  • Corticosteroids (such as prednisolone)

This information does not contain all possible interactions. Therefore, before using hydralazine, tell your doctor or pharmacist of all the products you use.


Taking too much hydralazine may cause the following:dizziness due to low blood pressure, fast heartbeat, uneven heartbeat, myocardial ischaemia (a painful heart condition due to lack of oxygen to the heart muscle) and coma.

If you think you, or someone you care for, might have accidentally taken more than the recommended dose of hydralazine or intentional overdose is suspected, contact your local hospital, GP or if in England call 111. In Scotland call NHS 24. In Wales, call NHS Direct Wales. In the case of medical emergencies, always dial 999.


If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

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Source: Selected from data included with permission and copyrighted by Boots UK Limited. This copyrighted material is sourced from a licensed data provider and is not for distribution, except as may be authorised by the applicable terms of use.
CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgement of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse events, nor should it be construed to indicate that use of a particular medicine is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any medicine, changing any diet, or discontinuing any course of treatment.

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