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Calcium Channel Blocker (Antihypertensive / Tocolytic) Pregnancy: C — used in pregnancy

Nifedipine

Brand names: Adalat, Adalat LA, Adalat Retard

Adult dose

Dose: Acute HTN in pregnancy: 10–20mg oral (immediate-release), repeat after 30 min if needed. Maintenance: LA 30–90mg OD. Tocolysis: 20mg oral loading, then 10–20mg every 3–6h
Route: Oral
Frequency: Per indication
AVOID sublingual route (severe hypotension). NICE: 1st or 2nd line for acute/maintenance HTN in pregnancy.

Clinical pearls

  • Preferred oral antihypertensive in pregnancy — evidence base and safety profile
  • Tocolysis: unlicensed indication but widely used — superior to ritodrine (fewer side effects)
  • Headache is the commonest complaint — warn patients; may require paracetamol
  • NEVER use sublingual nifedipine capsules — causes precipitous BP drop and fetal distress

Contraindications

  • Concurrent MgSO4 use (additive neuromuscular blockade risk — use with caution)
  • Cardiogenic shock
  • Unstable angina

Side effects

  • Headache (common)
  • Flushing
  • Palpitations
  • Peripheral oedema
  • Reflux oesophagitis

Interactions

  • Magnesium sulphate — additive tocolytic effect and neuromuscular blockade
  • Grapefruit juice — increases nifedipine levels (avoid)

Monitoring

  • Blood pressure
  • Fetal heart rate (CTG if tocolysis)
  • Maternal HR and symptoms

Reference: NICE NG133 Hypertension in Pregnancy; RCOG Tocolysis Guideline. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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