Formulary
Hydralazine hydrochloride: Indications, Dosing, Side Effects and Interactions
Hydralazine hydrochloride clinical drug profile including indications, dosing, side effects, cautions and interactions.
MedNext Academy | 4 min read
Hydralazine hydrochloride: Indications, Dosing, Side Effects and Interactions
Hydralazine hydrochloride clinical drug profile including indications, dosing, side effects, cautions and interactions.
Indications and dose
**Moderate to severe hypertension (adjunct)**
- **Adult** (By Mouth): Initially 25 mg twice daily, increased if necessary up to 50 mg twice daily.
**Heart failure (with long acting nitrate) (initiated in hospital or under specialist supervision)**
- **Adult** (By Mouth): Initially 25 mg 3-4 times a day, subsequent doses to be increased every 2 days if necessary; usual maintenance 50-75 mg 4 times a day.
**Hypertensive emergencies (including during pregnancy),Hypertension with renal complications**
- **Adult** (By Intravenous Infusion): Initially 200-300 micrograms/minute; usual maintenance 50-150 micrograms/minute.
- **Adult** (By Slow Intravenous Injection): 5-10 mg, to be diluted with 10 mL sodium chloride 0.9%; dose may be repeated after 20-30 minutes.
**Resistant hypertension (adjunct) for hydralazine hydrochloride**
- **Neonate** (By mouth): 250-500 micrograms/kg every 8-12 hours, increased if necessary to 2-3 mg/kg every 8 hours.
- **Child 1 month-11 years** (By mouth): 250-500 micrograms/kg every 8-12 hours, increased if necessary to 7.5 mg/kg daily; maximum 200 mg per day.
- **Child 12-17 years** (By mouth): 25 mg twice daily, increased to 50-100 mg twice daily.
- **Neonate** (By slow intravenous injection): 100-500 micrograms/kg, dose may be repeated if necessary every 4-6 hours; maximum 3 mg/kg per day.
- **Child 1 month-11 years** (By slow intravenous injection): 100-500 micrograms/kg, dose may be repeated if necessary every 4-6 hours; maximum 3 mg/kg per day; maximum 60 mg per day.
- **Child 12-17 years** (By slow intravenous injection): 5-10 mg, dose may be repeated if necessary every 4-6 hours.
- **Neonate** (By continuous intravenous infusion): 12.5-50 micrograms/kg/hour, continuous intravenous infusion is the preferred route in cardiac patients; maximum 2 mg/kg per day.
- **Child 1 month-11 years** (By continuous intravenous infusion): 12.5-50 micrograms/kg/hour, continuous intravenous infusion is the preferred route in cardiac patients; maximum 3 mg/kg per day.
- **Child 12-17 years** (By continuous intravenous infusion): 3-9 mg/hour, continuous intravenous infusion is the preferred route in cardiac patients; maximum 3 mg/kg per day.
Cautions
Cerebrovascular disease; coronary artery disease (may provoke angina, avoid after myocardial infarction until stabilised); occasionally blood pressure reduction too rapid even with low parenteral doses
Contraindications
Acute porphyrias ; cor pulmonale; dissecting aortic aneurysm; high output heart failure; idiopathic systemic lupus erythematosus; myocardial insufficiency due to mechanical obstruction; severe tachycardia
Side effects
Common or very common Angina pectoris; diarrhoea; dizziness; flushing; gastrointestinal disorders; headache; hypotension; joint disorders; lupus-like syndrome (after long-term therapy with over 100 mg daily (or less in women and in slow acetylator individuals)); myalgia; nasal congestion; nausea; palpitations; tachycardia; vomiting Rare or very rare Acute kidney injury; agranulocytosis; anaemia; anxiety; appetite decreased; conjunctivitis; depression; dyspnoea; eosinophilia; eye disorders; fever; glomerulonephritis; haematuria; haemolytic anaemia; hallucination; heart failure; hepatic disorders; leucocytosis; leucopenia; lymphadenopathy; malaise; nerve disorders; neutropenia; oedema; pancytopenia; paradoxical pressor response; paraesthesia; pleuritic pain; proteinuria; skin reactions; splenomegaly; thrombocytopenia; urinary retention; vasculitis; weight decreased Side-effects, further information The incidence of side-effects is lower if the dose is kept below 100mg daily, but systemic lupus erythematosus should be suspected if there is unexplained weight loss, arthritis, or any other unexplained ill health.
Interactions
**Other interactions (6):**
- Potentiation of effects: Concurrent therapy with other antihypertensives (vasodilators, calcium antagonists, ACE inhibitors, diuretics), anaesthetics, tricyclic antidepressants, major...
- Administration of Apresoline/Hydralazine Tablets shortly before or after diazoxide may give rise to marked hypotension.
- MAO inhibitors should be used with caution in patients receiving Apresoline/Hydralazine Tablets.
- Concurrent administration of Apresoline/Hydralazine Tablets with beta-blockers subject to a strong first pass effect (e.g.
- Downward adjustment of these drugs may be required when they are given concomitantly with Apresoline/Hydralazine Tablets.
- There is potential for the hypotensive effect of hydralazine to be antagonised when used concomitantly with oestrogens, corticosteroids or non-steroidal anti-inflammatory drugs.
Pregnancy
Hypertensive emergencies (including during pregnancy), Hypertension with renal complications for hydralazine hydrochloride By intravenous infusion Adult Initially 200-300 micrograms/minute; usual maintenance 50-150 micrograms/minute. By slow intravenous injection Adult 5-10 mg, to be diluted with 10 mL sodium chloride 0.9%; dose may be repeated after 20-30 minutes.
Breast feeding
Present in milk but not known to be harmful. Monitoring in breast feeding Monitor infant in breast-feeding.
Hepatic impairment
Manufacturer advises caution (risk of accumulation). Dose adjustments Manufacturer advises adjust dose or dosing interval according to clinical response.
Renal impairment
Dose adjustments See Prescribing in renal impairment . Manufacturer advises adjust dose or dosing interval according to clinical response if creatinine clearance less than 30 mL/minute (risk of accumulation).
Medicinal forms
Tablet,Tablet,Solution
Clinical governance
**Author:** MedNext Clinical Team. **Clinical reviewer:** Dr Shameer Deen, MBBS, MS, MRCS. **Sources:** BNF, Indian Pharmacopoeia, CIMS India. **Correction:** Report errors at support@mednext.academy.
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