What is a Patient Information Leaflet and why is it useful?

The Patient Information Leaflet (PIL) is the leaflet included in the pack with a medicine. It is written for patients and gives information about taking or using a medicine. It is possible that the leaflet in your medicine pack may differ from this version because it may have been updated since your medicine was packaged.

Below is a text only representation of the Patient Information Leaflet. The original leaflet can be viewed using the link above.

The text only version may be available in large print, Braille or audio CD. For further information call emc accessibility on 0800 198 5000. The product code(s) for this leaflet is: PL 20072/0230.

Hydralazine 20mg Powder for Concentrate for Solution for Injection/Infusion

Package leaflet: Information for the patient


Hydralazine 20mg Powder for Concentrate for Solution for Injection/Infusion

Hydralazine hydrochloride

Read all of this leaflet carefully before you start taking this medicine because it contains important information for you

  • Keep this leaflet. You may need to read it again.
  • If you have any further questions ask your doctor, pharmacist or nurse.
  • This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their symptoms are the same as yours.
  • If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. See section 4.

The name of your medicine is Hydralazine 20mg Powder for Concentrate for Solution for Injection/Infusion referred to from now as Hydralazine Injection.

What is in this leaflet:

1. What Hydralazine injection is and what it is used for
2. What you need to know before you are given Hydralazine Injection
3. How Hydralazine Injection is given
4. Possible side effects
5. How to store Hydralazine Injection
6. Contents of the pack and other information


The name of your medicine is Hydralazine Injection.

The active ingredient is hydralazine hydrochloride in the form of a powder. Hydralazine hydrochloride belongs to a group of medicines called antihypertensives.

Hydralazine Injection is used to treat very high blood pressure, particularly when this condition occurs in pregnancy or in people with kidney disease.

It works by relaxing blood vessels which increases the supply of blood and oxygen to the heart.


You should not be given this medicine if you:

  • are allergic to hydralazine, dihydralazine or any of the other ingredients in this medicine (listed in section 6) (allergic reactions include mild symptoms such as itching and/or rash. More severe symptoms include swelling of the face, lips, tongue and/or throat with difficulty in swallowing or breathing);
  • have or have ever had a condition called Systemic Lupus Erythematosus (SLE), an autoimmune condition which causes joint pain, skin rashes and fever;
  • suffer from severe tachycardia or right sided heart failure due to increased pressure in the blood vessels of the lungs (cor pulmonale);
  • suffer from thyrotoxicosis (an excess of thyroid hormones in the blood that can cause a fast heartbeat, sweating, trembling, anxiety, increased appetite, loss of weight and intolerance of heat);
  • heart function impaired (myocardial insufficiency);
  • have a condition known as porphyria.

Warnings and precautions:

Talk to your doctor or pharmacist or nurse before taking Hydralazine Injection if you

  • have had a heart attack in the past three months;
  • have angina pectoris, which causes pain in the chest with exercise;
  • have cerebrovascular disease (narrowing of the blood vessels in the brain);
  • have been told you are a slow acetylator (this means that your body handles some medicines more slowly than other people);
  • suffer from any serious liver or kidney problems;
  • have blockage of one or more arteries that supply blood to the heart (coronary heart disease).

If any of the above apply to you, or if you are not sure, tell your doctor before receiving Hydralazine Injection.


Hydralazine Injection is not recommended for use in children.

Other medicines and Hydralazine Injection

Tell your doctor or pharmacist if you are taking, have recently taken or might take any other medicines.

It is especially important that you tell your doctor if you are taking:

  • medicines for high blood pressure, such as vasodilators (e.g. minoxidil, diazoxide);
  • ACE inhibitors (e.g. enalapril, lisinopril, captopril);
  • beta-blockers (e.g. propranolol);
  • calcium antagonists (e.g. nifedipine, diltiazem);
  • medicines for water retention (e.g. diuretics);
  • medicines for problems such as depression, including monoamine oxidase inhibitors (MAOIs) (e.g. moclobemide, phenelzine, isocarboxazid, tranylcypromine), tricyclic antidepressants (e.g. amitriptyline, clomipramine) or tranquillisers (e.g. diazepam);
  • medicines to control pain and inflammation (a group of medicines known as non-steroidal anti-inflammatory drugs (NSAIDs));
  • medicines to control psychoses;
  • a specific group of medicines known as nitrates, used to control blood pressure;
  • oestrogens (a group of female sex hormones used in contraception and in treating the menopause).

If you are going to have a general anaesthetic you should tell the doctor or dentist in charge that you are taking Hydralazine Injection.

Hydralazine Injection with food, drink and alcohol

It is advisable not to drink alcohol whilst taking Hydralazine Injection as it may affect you more than usual.

Pregnancy, breast-feeding and fertility

If you are pregnant or breast-feeding, think you may be pregnant or are planning to have a baby, ask your doctor or pharmacist for advice before taking this medicine.

Driving and using machines

You can drive while being treated with Hydralazine Injection but do not drive until you know how it affects you. It may make you feel dizzy or impair your reactions. If it affects you in this way, do not drive or operate any machinery.


Always take this medicine exactly as your doctor has told you. Check with your doctor if you are not sure.

This medicine will be given to you in hospital. Your doctor will decide when and how to treat you with this medicine. It can be given to you in one of 2 ways:

  • usually it is injected slowly into your vein using a syringe, this is called an intravenous injection or;
  • it may be diluted further and injected very slowly into your vein through a drip (intravenous infusion).

The recommended dose is 5 to 10 mg by intravenous injection, and will be repeated if necessary after 20 to 30 minutes.

Your blood pressure will be taken whilst you are receiving treatment and the dose adjusted to make sure that you have gradual fall in your blood pressure to normal levels.

If you are given more medicine than you should

As this medicine is given to you in hospital it is very unlikely that an overdose will happen.

Should an overdose occur, the doctor will treat any symptoms that follow.


Like all medicines, this medicine can cause side effects, although not everybody gets them.

Stop taking the medicine and seek immediate medical advice if you notice the following:

  • SLE-type syndrome, which can cause symptoms such as joint pain, fever, change in blood count and skin rash.
  • Allergic reactions including itching, skin rash, inflammation of the walls of small blood vessels and difficulty in breathing.
  • Yellowing of the skin and whites of the eyes, which may indicate problems with the liver such as jaundice and hepatitis.
  • Kidney failure (e.g. changes in urine, swelling of legs, ankles or feet, shortness of breath, tiredness and nausea).

Other side effects may include:

Very common (may affect more than 1 in 10 people)

  • Abnormal heart beat (palpitations);
  • An unusually fast heart beat;
  • Headaches.

Common (may affect up to 1 in 10 people)

  • Chest pains;
  • Swelling and/or pain in joints, muscle pain;
  • Low blood pressure;
  • Feeling sick and being sick, particularly at the beginning of the treatment or after an increase in dose;
  • Diarrhoea;
  • Flushing.

Rare (may affect up to 1 in 1,000 people)

  • Heart failure, swelling;
  • Increased levels of a substance called creatinine in the blood;
  • Breathlessness, breathing difficulties or pain when breathing;
  • Skin rash;
  • Blood in the urine which may be associated with a disease of the kidneys;
  • Presence of protein in the urine;
  • Inflammation or the abnormal functioning of the liver;
  • Watering or sore itchy eyes;
  • A reduction in the number of platelets in the blood which can cause unexplained bruising or rashes;
  • A reduction in red blood cells, which can make you feel tired or breathless with physical exertion;
  • A reduction in certain white blood cells which may make you more susceptible to infections;
  • Fever;
  • Anxiety;
  • Restlessness;
  • Blocked or stuffy nose;
  • Loss of appetite;
  • Weight loss;
  • Dizziness;
  • Generally feeling unwell.

Isolated cases

  • A change in the amount of urine produced;
  • A restriction of movement in part of the intestine;
  • A deficiency of certain white blood cells which can result in fever and ulceration of the mouth and throat;
  • An increased number of white blood cells;
  • Enlargement of the spleen;
  • A reduction in the number of red and white blood cells and platelets in the blood;
  • Depression;
  • Seeing or hearing things which are not really there (hallucinations);
  • Inflammation of the nerves which may cause weakness or numbness especially in your fingers and toes;
  • Tingling (pins and needles) in your hands or feet;
  • Disease of the lymph nodes;
  • Enlarged eye balls;
  • The inability to completely or partially empty the bladder;
  • Opposite effect of medical treatment (episodes of high blood pressure);
  • An increase in other kinds of white blood cells.

If you feel very tired, experience unexpected bruising or bleeding, or more infections (e.g. colds and sore throats) than usual please tell your doctor.

Your doctor may decide to conduct tests on your blood periodically as a result of these symptoms.

If any of the side effects becomes severe, or you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist immediately.

Reporting of side effects

If you get any side effects, talk to your doctor, pharmacist or nurse. This includes any possible side effects not listed in this leaflet. You can also report side effects directly via the Yellow Card Scheme at: www.mhra.gov.uk/yellowcard or search for MHRA Yellow Card in the Google Play or Apple App Store

By reporting side effects you can help provide more information on the safety of this medicine.


Keep this medicine out of the sight and reach of children.

The ampoules will be stored in the hospital and they will follow the instructions below.

The ampoules should be protected from light and stored below 30°C.

Do not use this medicine after the expiry date which is stated on the label. The expiry date refers to the last day of the month. The solution will be used as soon as it has been made up.


What Hydralazine Injection contains

Each ampoule contains 20 mg of the active ingredient, hydralazine hydrochloride as a powder.

They also contain hydrochloric acid (as an inactive ingredient).

What Hydralazine Injection looks like and contents of the pack

Hydralazine Injection is provided as a white to yellow powder in 2 ml clear glass ampoules.

Each pack contains 5 ampoules.

Marketing Authorisation Holder and Manufacturer

Amdipharm UK Limited
Capital House
85 King William Street
United Kingdom

Alternate Manufacturer

52 Rue Marcel ET Jacques Gaucher
Fontenay Sous Bois

Date of leaflet August 2019