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Direct vasodilator

Hydralazine hydrochloride

Brand names: Apresoline

Adult dose

Dose: PO 25–50mg BD–QDS (max 200mg/day). IV (hypertensive emergency, esp. pregnancy): 5–10mg slow IV every 20–30 min, or 200–300 micrograms/min infusion
Route: PO/IV/IM
Frequency: BD-QDS

Clinical pearls

  • IV hydralazine is a workhorse for hypertensive emergency in pregnancy/eclampsia (alongside labetalol)
  • Combine with nitrate + diuretic in HFrEF (especially Black patients)
  • Pre-treat with β-blocker to limit reflex tachycardia

Contraindications

  • SLE
  • Severe tachycardia
  • High-output heart failure
  • Cor pulmonale
  • Dissecting aortic aneurysm
  • Idiopathic SLE

Side effects

  • Reflex tachycardia
  • Headache
  • Drug-induced lupus
  • Fluid retention
  • Polyneuropathy (with isoniazid)

Interactions

  • Other antihypertensives (additive)
  • NSAIDs (reduce effect)
  • MAOIs

Monitoring

  • BP
  • HR
  • ANA if long-term
  • FBC

Reference: BNF; NICE NG133; ESC guidelines; https://bnf.nice.org.uk/drugs/hydralazine-hydrochloride/. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.