First-lineAdalat
Nifedipine (Tocolysis)
Calcium channel blocker (off-label tocolytic)
Preferred tocolytic to buy 48 h for steroids and in-utero transfer.
Oral (immediate-release)
First-line for
- Threatened preterm labour 24–34 weeks (≤48 h)
Mechanism
Blocks L-type Ca²⁺ channels in myometrium → ↓ contractile force.
“20-20-20 / 20q6”
- 20 mg PO loading
- Repeat 20 mg after 30 min if contractions continue
- Then 20 mg q6h for ≤48 h
Dosing
- Loading
- 20 mg PO, repeat after 30 min if needed (max 40 mg/h)
- Maintenance
- 20 mg PO q6–8 h for up to 48 h
Contraindications
- AbsoluteCardiac disease, severe hypotension
- AbsolutePlacental abruption, chorioamnionitis, fetal compromise
Side effects
- Headache, flushing
- Hypotension, tachycardia
- Pulmonary oedema (with steroids/fluids)
Fetal & maternal notes
- • Better neonatal outcomes vs β-agonists.
- • Safe maternal profile.
Key interactions
MgSO₄
AvoidProfound hypotension + neuromuscular block — avoid combo
β-agonists (salbutamol)
AvoidPulmonary oedema
Clinical pearls
- 💡 Strictly limit IV fluids to 80 mL/h.
- 💡 Stop if BP <90/50 or maternal HR >120.
Content last reviewed: REPLACE_ME (e.g. 2026-07)
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