Hydralazine

Registered South African indications:

• Hypertension

Contraindications

• Hypersensitivity to the active ingredient or any of its excipients
• Tachycardia
• Cardiac failure due to aortic or mitral stenosis
• Cardiac failure due to constrictive pericarditis
• High output cardiac failure
• Cor pulmonale
• Systemic lupus erythematosus 
• Dissecting aortic aneurysm
• Porphyria
• Thyrotoxicosis

Cautions

• Pregnancy
• Breastfeeding
• Renal impairment
• Hepatic impairment
• Elderly
• Coronary artery disease
• Cerebrovascular disease
• Recent myocardial infarction
• High doses and long duration of treatment
• Slow acetylators
• Surgery
• Galactose intolerance
• Lapp lactase deficiency
• Glucose-galactose malabsorption

Forms avail. in SA and covered in this monograph: tab

Hypertension - moderate to severe

• Oral (tab): Initial: 10-20mg, 6-12hrly; Titrate slowly; Maintenance: 100-200mg, dly; Max: 300mg/24hrs 

Congestive cardiac failure - moderate to severe

• Oral (tab): Initial, 25-50mg, 6-12hrly; Maintenance: 50-75mg, 6hrly

Initiation of treatment for congestive cardiac failure: this should always be done in hospital under close supervision until patient stabilised on maintenance dose

Discontinuation of treatment in congestive cardiac failure should be done gradually

Not established for use in children

Pregnancy

• Caution
• Hydralazine readily crosses the placenta with serum concentrations in the foetus being equal to or greater than those in the mother. Animal studies have shown reproductive toxicity. No serious adverse effects in human pregnancy have been reported with hydralazine use during the third trimester. Thrombocytopenia, leucopenia, petechial bleeding and haematomas have been reported in newborns whose mother took hydralazine, though these symptoms resolved spontaneously in one to three weeks
• Hydralazine should be avoided during the first and second trimesters of pregnancy but may be used later in pregnancy if the mother or foetus is at risk (eg pre-eclampsia, eclampsia) or if no safer alternative is available

Breastfeeding

• Caution
• Hydralazine passes into breast milk but reports to date have not indicated adverse effects on the infant. Breastfed infants of mothers taking hydralazine should be observed for possible adverse effects

Renal Impairment

• Caution; dose adjustment recommended

*Adjustments based on doses of 25-50mg every 8hrs

Hepatic Impairment

• Caution; no dose adjustment recommended 
  High-risk patients: Avoid use or exercise extreme caution (See additional prescribing points)

Elderly

• Caution; no dose adjustment recommended 

Porphyria Information

• Porphyrinogenic (P)

Drugs in Sport

• Permitted - No warnings

Central Nervous System Disorders

• Agitation
• Anorexia
• Anxiety
• Depression
• Hallucinations
• Headache
• Dizziness
• Peripheral neuritis
• Polyneuritis
• Paraesthesia

Cardiovascular Disorders

• Tachycardia
• Palpitations
• Flushing
• Hypotension
• Anginal symptoms
• Oedema
• Heart failure
• Paradoxical pressor responses
• Fluid retention

Respiratory Disorders

• Nasal congestion
• Dyspnoea
• Pleural pain

Gastrointestinal Disorders

• Diarrhoea
• Nausea and vomiting

Hepatobiliary Disorders

• Jaundice
• Liver enlargement
• Abnormal liver functions

Genitourinary Disorders

• Proteinuria
• Increased plasma creatinine
• Haematuria
• Acute renal failure
• Urinary retention
• Glomerulonephritis

Musculoskeletal Disorders

• Arthralgia
• Joint swelling
• Myalgia
• Rheumatoid arthritis

Skin and Subcutaneous Tissue Disorders

• Systemic lupus erythematosus-like syndrome
• Rash
• Pruritus
• Urticaria
• Vasculitis

Immune, Blood and Lymphatic System Disorders

• Anaemia
• Leucopenia
• Neutropenia
• Thrombocytopenia with or without purpura
• Haemolytic anaemia
• Leucocytosis
• Lymphadenopathy
• Pancytopenia
• Splenomegaly
• Agranulocytosis

Sensory Disorders

• Increased lacrimation
• Conjunctivitis
• Exophthalmos

• Antihypertensives
• Muscle relaxants
• Anaesthetics
• Tricyclic antidepressants
• Nitrates
• Central nervous system depressants
• Diazoxide
• Monoamine oxidase inhibitors
• Beta-blockers
• Oestrogens
• Non-steroidal anti-inflammatory drugs
• Sympathomimetics 
• Corticosteroids

None routine. Specific cases may require

• Cardiac monitoring
• Antinuclear factors
• Urine analysis

Hepatic Impairment

Hydralazine must be used with caution or avoided in the following:

• Auto-immune disorders (SLE, RA, IBD, vasculitis, etc)
• Patients on immunosuppressant therapy (Sirolimus, tacrolimus, cyclosporine, methotrexate, etc)
• Patients with hepatic pathologies (liver cirrhosis, chronic alcoholism, hepatitis, etc)
• Patients on concomitant hepatotoxic therapy (Rifampicin, methotrexate nevirapine, allopurinol etc)

Hydralazine is a direct acting vasodilator which exerts its effects principally on the arterioles. Administration of hydralazine produces a fall in peripheral vascular resistance and a decrease in arterial blood pressure.

Tablet 10mg

• Hyperphen (Pharmacare)

Tablet 25mg

• Sandoz Hydralazine (Sandoz)

Tablet 50mg

• Hyperphen (Pharmacare)
• Sandoz Hydralazine (Sandoz)