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Oxytocin Receptor Antagonist (Tocolytic) Pregnancy: Indicated in pregnancy (24–33+6 weeks) for tocolysis

Atosiban (Tocolysis)

Brand names: Tractocile

Adult dose

Dose: Loading: 6.75 mg IV bolus over 1 min. Then: 18 mg/hr IV infusion for 3h. Then: 6 mg/hr IV infusion for up to 45h. Maximum treatment course: 48h
Route: IV infusion
Frequency: Loading then continuous infusion
Max: 330 mg total per treatment course
NICE NG25 recommended tocolytic for preterm labour 24–33+6 weeks gestation. Repeat courses may be given up to 3 times. Dilute in normal saline, Hartmann's, or glucose. Requires confirmation of preterm labour with TVU cervical length or clinical criteria.

Paediatric dose

Route: N/A
Frequency: N/A
Max: N/A
Not applicable in paediatric patients

Dose adjustments

Renal

No dose adjustment required

Hepatic

No dose adjustment required

Clinical pearls

  • NICE NG25 recommends atosiban as first-line tocolytic for preterm labour (24–33+6 weeks) — fewer side effects than nifedipine or beta-agonists
  • Tocolysis goal: delay delivery by 48h to allow corticosteroids (betamethasone) to act and maternal transfer to tertiary centre
  • NOT licenced below 24 weeks gestation
  • Up to 3 repeat courses may be given in recurrent preterm labour
  • More expensive than nifedipine but better maternal tolerability profile — preferred in UK obstetric practice

Contraindications

  • Gestational age <24 weeks or >33+6 weeks
  • Premature rupture of membranes >30 weeks
  • Fetal growth restriction with abnormal fetal heart rate
  • Placenta praevia or unexplained antepartum haemorrhage
  • Eclampsia or severe pre-eclampsia
  • Intrauterine infection
  • Fetal distress or demise

Side effects

  • Nausea (common)
  • Headache
  • Flushing
  • Tachycardia (less than beta-agonists)
  • Injection site reactions
  • Hyperglycaemia (rare)

Interactions

  • Other tocolytics — additive cardiovascular effects (nifedipine caution)

Monitoring

  • Uterine contractions (frequency/duration)
  • Fetal heart rate (continuous CTG)
  • Maternal BP, HR
  • Signs of preterm labour progression

Reference: BNFc; NICE NG25 Preterm Labour and Birth; BNF; 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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