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

Active Ingredient:
hydralazine hydrochloride
ADVANZ Pharma See contact details
ATC code: 
About Medicine
{healthcare_pro_orange} This information is for use by healthcare professionals
Last updated on emc: 07 May 2024
1. Name of the medicinal product

Apresoline Ampoules 20 mg

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

2. Qualitative and quantitative composition

The active ingredient is 1-hydralainophthalazine hydrochloride (hydralazine hydrochloride). Each 2 ml ampoule contains 20mg hydralazine hydrochloride.

For the full list of excipients, see section 6.1.

3. Pharmaceutical form

Ampoules containing powder for concentrate for solution for injection/infusion

White to yellow lyophilisate (pellet)

4. Clinical particulars
4.1 Therapeutic indications


Treatment of hypertensive emergencies, particularly those associated with pre-eclampsia and toxaemia of pregnancy.


Treatment of hypertension with renal complications

4.2 Posology and method of administration



Clinical evidence would indicate that no special dosage regime is necessary. Advancing age does not affect either blood concentration or systemic clearance. Renal elimination may however be affected in so far as kidney function diminishes with age.


Initially 5 to 10 mg by slow intravenous injection, to avoid precipitous decreases in arterial pressure with a critical reduction in cerebral or utero-placental perfusion. If necessary a repeat injection can be given after an interval of 20-30 minutes, throughout which blood pressure and heart rate should be monitored. A satisfactory response can be defined as a decrease in diastyloic blood pressure to 90/100 mmHg. The contents of the vial should be reconstituted by dissolving in 1 ml of water for injection BP. This should then be further diluted with 10 ml of Sodium Chloride injection BP 0.9% and be administered by slow intravenous injection. The injection must be given immediately and any remainder discarded. Hydralazine may also be given by continuous intravenous infusion, beginning with a flow rate of 200-300µ g/min. Maintenance flow rates must be determined individually and are usually within the range 50-150µ g/min. The product reconstituted as for direct iv injection may be added via the infusion container to 500 ml of Sodium Chloride Injection BP 0.9% and given by continuous infusion. The addition should be made immediately before administration and the mixture should not be stored. Hydralazine for infusion can also be used with 5% sorbitol solution or isotonic inorganic infusion solutions such as Ringers solution.

Paediatric population:

The safety and efficacy of Apresoline Ampoules 20 mg/ Hydralazine 20mg Powder for Concentrate for Solution for Injection/Infusion in children have not yet been established.

Method of administration

For Intravenous use only.

4.3 Contraindications

Hypersensitivity to the active substance or to any of the excipients listed in section 6.1

Known hypersensitivity to dihydralazine.

Idiopathic systemic lupus erythematosus (SLE) and related diseases.

Severe tachycardia and heart failure with a high cardiac output (e.g. in thyrotoxicosis).

Myocardial insufficiency due to mechanical obstruction (e.g. in the presence of aortic or mitral stenosis or constrictive pericarditis).

Isolated right ventricular failure due to pulmonary hypertension (cor pulmonale).

Dissecting aortic aneurysm.


4.4 Special warnings and precautions for use

Cardiovascular system

The overall 'hyperdynamic' state of the circulation induced by hydralazine may accentuate certain clinical conditions. Myocardial stimulation may provoke or aggravate angina pectoris. Hydralazine can cause anginal attacks and ECG changes indicative of myocardial ischaemia. It must therefore be used with caution in patients with suspected coronary artery disease or with cerebrovascular disease. Patients with suspected or confirmed coronary artery disease should therefore be given Apresoline Tablets only under beta-blocker cover or in combination with other suitable sympatholytic agents. It is important that the beta-blocker medication should be commenced a few days before the start of treatment with Apresoline Tablets.

When undergoing surgery, patients treated with Apresoline/Hydralazine Tablets may show a fall in blood pressure, in which case one should not use adrenaline to correct the hypotension, since it enhances the cardiac-accelerating effects of hydralazine.

Patients who have survived a myocardial infarction should not receive Apresoline Tablets until a post-infarction stabilisation phase has been achieved.

When initiating therapy in heart failure, particular caution should be exercised and the patient kept under surveillance and/or haemodynamic monitoring for early detection of postural hypotension or tachycardia. Where discontinuation of therapy in heart failure is indicated, Apresoline/Hydralazine Tablets should be withdrawn gradually (except in serious situations, such as SLE-like syndrome or blood dyscrasias) in order to avoid precipitation and/or exacerbation of heart failure.

Immune system

Prolonged treatment with hydralazine may provoke a systemic lupus erythematosus (SLE)-like syndrome,. First symptoms are likely to be similar to rheumatoid arthritis (arthralgia, sometimes associated with fever, anaemia, leucopenia, thrombocytopenia and rash) and are reversible after withdrawal of the drug. In its more severe form it resembles acute SLE (similar manifestations as the milder form plus pleurisy, pleural effusions and pericarditis), and in rare cases renal and ocular involvement have been reported. Early detection and a timely diagnosis with appropriate therapy (i.e. treatment discontinuation and possibly long-term treatment with corticosteroids may be required to reverse these changes) are of utmost importance in this life-threatening illness to prevent more severe complications, which may sometimes be fatal.

Treatment with hydralazine may induce systemic vasculitis. There have also been a small number of reported cases of suspected antineutrophil cytoplasmic antibody ANCA(+) vasculitis in some patients also receiving hydralazine, leading to pulmonary renal syndrome which is a combination of diffuse alveolar haemorrhage and rapidly progressive glomerulonephritis. Patients may present with severe respiratory and/or renal failure and require early diagnosis, discontinuation of the medicine and prompt hospital treatment. The syndrome is characterised by a fulminant course if left untreated, and may sometimes be fatal.

Since such reactions tend to occur more frequently the higher the dose and the longer its duration, and since they are also more common in slow acetylators, it is recommended that for maintenance therapy the lowest effective dose should be used. If 100 mg daily fails to elicit an adequate clinical effect, the patient's acetylator status should be evaluated. Slow acetylators and women run greater risk of developing the SLE-like syndrome and every effort should therefore be made to keep the dosage below 100 mg daily and a careful watch kept for signs and symptoms suggestive of this syndrome. If such symptoms do develop the drug should be gradually withdrawn.

Rapid acetylators often respond inadequately even to doses of 100 mg daily and therefore the dose can be raised with only a slightly increased risk of an SLE like syndrome.

During long term treatment with Apresoline Tablets it is advisable to determine the antinuclear factors and conduct urine analysis at intervals of approximately 6 months. Microhaematuria and / or proteinuria, in particular together with positive titres of ANF, may be initial signs of immune-complex glomerulonephritis associated with the SLE like syndrome. If overt clinical signs or symptoms develop, the drug should be withdrawn immediately. A complete blood count and ANF titre determination is indicated before and periodically during prolonged therapy with hydralazine even if the patient is asymptomatic. These studies are also indicated if the patient develops arthralgia, fever, chest pain, persistent malaise, or other unexplained signs or symptoms. A positive ANF titre requires that the physician carefully weighs the implications of the test results against the benefits of continued therapy with hydralazine

Nervous system

Isolated cases of peripheral neuritis in the form of paraesthesia has been reported, and may respond to pyridoxine administration or drug withdrawal.

Haematological effects

Adverse haematological effects, such as a reduction in haemoglobin and red cell count, leucopoenia, agranulocytosis and purpura, have been reported in a very few cases. If such abnormalities develop, therapy should be discontinued.

Genetic effects

In high (cyto-) toxic concentrations, hydralazine induces gene mutations in single cell organisms and in mammalian cells in vitro. No unequivocally mutagenic effects have been detected in vivo in a great number of test systems.


Skin rash, febrile reactions and change in blood count occur rarely and the drug should be withdrawn.

Driving and using machines

Dizziness or hypotension may occur with Apresoline with established mechanism of action, it is therefore advisable to exercise caution when driving or operating machinery.

This medicine contains sucrose

Patients with rare hereditary problems of fructose intolerance, glucose-galactose malabsorption or sucrase-isomaltase insufficiency should not take this medicine.

4.5 Interaction with other medicinal products and other forms of interaction

Potentiation of effects: Concurrent therapy with other antihypertensives (vasodilators, calcium antagonists, ACE inhibitors, diuretics), anaesthetics, tricyclic antidepressants, major tranquillisers, nitrates or drugs exerting central depressant actions (including alcohol).

Administration of Hydralazine shortly before or after diazoxide may give rise to marked hypotension.

MAO inhibitors should be used with caution in patients receiving Hydralazine.

Concurrent administration of Hydralazine with beta-blockers subject to a strong first pass effect (e.g. propranolol) may increase their bioavailability. Download adjustment of these drugs may be required when they are given concomitantly with Hydralazine.

There is potential for the hypotensive effect of hydralazine to be antagonised when used concomitantly with oestrogens or non-steroidal anti-inflammatory drugs.

4.6 Fertility, pregnancy and lactation


Use of Hydralazine in pregnancy, before the third trimester should be avoided but the drug maybe employed in later pregnancy if there is no safer alternative or when the disease itself carries serious risks for the mother or child e.g. pre-eclampsia and /or eclampsia.

No serious adverse effects in human pregnancy have been reported to date with Hydralazine, although experience in the third trimester is extensive.


Hydralazine passes into breast milk but reports available so far have not shown adverse effects on the infant. Mothers in whom use of Hydralazine proves unavoidable may breast feed their infant provided that the infant is observed for possible adverse effects.


No data available.

4.7 Effects on ability to drive and use machines

Hydralazine may impair the patient's reactions especially at the start of the treatment. The patient should be warned of the hazard when driving or operating machinery.

4.8 Undesirable effects

Some of the adverse effects listed below e.g. tachycardia, palpitations, angina symptoms, flushing, headache, dizziness, nasal congestion and gastro-intestinal disturbances are commonly seen at the start of treatment, especially if the dose is raised quickly. However such effects generally subside in the further course of treatment.

(The following frequency estimates are used: Very common (≥ 1/10), common (≥ 1/100, < 1/10), rare (≥ 1/10000, < 1/1000); isolated cases (< 0.001%).

System Organ Class


Adverse effects

Blood and lymphatic system disorders


Anaemia, leucopenia, neutropenia, thrombocytopenia with or without purpura.


Isolated cases

Haemolytic anaemia, leucocytosis, lymphadenopathy, pancytopenia, splenomegaly, agranulocytosis

Immune system disorders

Not known

Vasculitis including pulmonary renal syndrome

Metabolism and nutrition disorders



Psychiatric disorders


Agitation, anxiety

Isolated cases

Depression, hallucinations

Nervous system disorders

Very common




Isolated cases

Peripheral neuritis, polyneuritis, paraesthesia (these unwanted effects may be reversed by administering pyridoxine).

Eye disorders


Conjunctivitis, lacrimation increased

Cardiac disorders

Very common:

Tachycardia, palpitations


Anginal symptoms


Oedema, heart failure

Vascular disorder


Flushing, hypotension

Isolated cases:

Paradoxical pressor responses

Respiratory, thoracic and mediastinal disorders


Nasal congestion, Dyspnoea, pleuritic pain

Gastrointestinal disorders


Gastrointestinal disturbances, diarrhoea, nausea, vomiting

Isolated cases

Paralytic ileus.

Hepatobiliary disorders


Jaundice, hepatomegaly, abnormal liver function sometimes in association with hepatitis.

Skin and subcutaneous tissue disorders


SLE-like syndrome (sometimes resulting in a fatal outcome see section 4.4 Special warnings and precautions for use)


Hypersensitivity reactions such as pruritus, urticaria, vasculitis, rash

Musculoskeletal and connective tissue disorders


Arthralgia, joint swelling, myalgia

Renal and urinary disorders


Proteinuria, Blood creatinine increased, haematuria sometimes in association with glomerulonephritis.

Isolated cases

Acute kidney failure, urinary retention.

General disorders and administration site conditions


Pyrexia, malaise.

Isolated cases




Weight decrease

Reporting of suspected adverse reactions

Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the Yellow Card Scheme Website: or search for MHRA Yellow Card in the Google Play or Apple App Store.

4.9 Overdose

Signs and Symptoms

Symptoms include hypotension, tachycardia, myocardial ischaemia dysrhythmias and coma.


Supportive measures including intravenous fluids are also indicated. If hypotension is present, an attempt should be made to raise the blood pressure without increasing the tachycardia. Adrenaline should therefore be avoided.

5. Pharmacological properties
5.1 Pharmacodynamic properties

Pharmacotherapeutic group: Hydrazinophthalazine derivatives, ATC code: C02DB02

Mechanism of action

Hydralazine is a direct acting vasodilator which exerts its effects principally on the arterioles. Its precise mode of action is not known.

Pharmacodynamic effects

Administration of hydralazine produces a fall in peripheral resistance and a decrease in arterial blood pressure, effects which induce reflex sympathetic cardiovascular responses. The concomitant use of a beta-blocker will reduce these reflex effects. and enhance the anti-hypertensive effect. The use of hydralazine can result in sodium and fluid retention, producing oedema and reduced urinary volume. These effects can be prevented by concomitant administration of a diuretic.

5.2 Pharmacokinetic properties


None stated


Hydralazine is rapidly distributed in the body and displays a particular affinity for the blood-vessel walls. Plasma protein binding is of the order of 90%.


None stated


Plasma half-life averages 2-3 hours but is prolonged up to 16 hours in severe renal failure (creatinine clearance less than 20 ml / min) and shortened to approximately 45 minutes in rapid acetylators.

Characteristics in patients

None stated

5.3 Preclinical safety data

Hydralazine has been found to be teratogenic in mice producing a small incidence of cleft palate and certain other bony malformations, in oral doses ranging from 20-120mg/kg i.e. 20-30 times the maximum human daily dose. It was not teratogenic in rats or rabbits.

6. Pharmaceutical particulars
6.1 List of excipients

Hydrochloric acid

6.2 Incompatibilities

Dextrose infusion solutions are not compatible because contact between hydralazine and glucose causes hydralazine to be rapidly broken down.

6.3 Shelf life

5 years.

Use immediately after reconstitution.

6.4 Special precautions for storage

Store in original package in order to protect from light. Store below 25 ° C.

For single use only.

For storage conditions after reconstitution of the medicinal product, see section 6.3.

6.5 Nature and contents of container

Colourless Type I glass 2ml ampoule. Five ampoules are packed in a cardboard printed carton.

6.6 Special precautions for disposal and other handling

No special requirements for disposal.

7. Marketing authorisation holder

Amdipharm UK Limited

Dashwood House,

69 Old Broad Street,

London, EC2M 1QS,

United Kingdom

8. Marketing authorisation number(s)

PL 20072/0230

9. Date of first authorisation/renewal of the authorisation

15 November 2001

10. Date of revision of the text


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