Atosiban
Also known as: Tractocile
Atosiban competitively antagonizes the myometrial oxytocin receptor (with affinity also for vasopressin V1a receptors), reducing the intracellular calcium rise and prostaglandin production that drive uterine contractions.
- Drug class
- Oxytocin receptor antagonist (tocolytic)
- Primary targets
- Oxytocin receptor, Vasopressin V1a receptor
- Dose reference
- Label reference (not a recommendation): 6.75 mg IV bolus over ~1 min, then 300 mcg/min infusion for 3 hours, then 100 mcg/min for up to 45 hours; max duration 48 hours
- Half-life
- Biexponential after IV infusion: initial ~0.2 hours, terminal ~1.7 hours
- Developer / origin
- Ferring Pharmaceuticals
- Reference year
- 2000
- Evidence score
- 4/5 - Approved (EU) with randomized controlled trial evidence
Approved uses
- Delay of imminent preterm birth in pregnant women with uncomplicated preterm labor (EU, roughly 24-33 weeks gestation)
Approved (EU) with randomized controlled trial evidence
Atosiban is EU-approved (Tractocile, 2000) as an intravenous tocolytic, supported by pharmacokinetic studies and randomized controlled trials versus beta-agonists showing comparable delay of preterm birth with better maternal tolerability; however, evidence for improving hard neonatal outcomes is modest and the drug is not FDA-approved.
Investigational compound with human randomized or phase 2/3 evidence.
Evidence basis
- EMA Summary of Product Characteristics and EPAR scientific discussion defining indication, dosing and contraindications
- Randomized double-blind controlled trial versus salbutamol (Worldwide Atosiban vs Beta-agonists Study Group, 2001)
- Pharmacokinetic studies in pregnant women with preterm contractions (Goodwin 1995, 1996)
- US placebo-controlled trial (Romero 2000) and subsequent FDA non-approval
Key references
- European Medicines AgencyTractocile (atosiban) Summary of Product Characteristics
- Eur J Obstet Gynecol Reprod Biol (PubMed)Treatment of preterm labour with the oxytocin antagonist atosiban: a double-blind, randomized, controlled comparison with salbutamol
- Am J Obstet Gynecol (PubMed)An oxytocin receptor antagonist (atosiban) in the treatment of preterm labor: a randomized, double-blind, placebo-controlled trial with tocolytic rescue
How to read this entry
Dose references and half-life values are pulled from trial protocols, labels, reviews, or published summaries where available. They are context for research and comparison, not a personal dosing recommendation.
Status matters: approved drugs have regulated indications; investigational compounds are still being studied; research-only peptides do not have established human dosing, safety, or efficacy for consumer use.
Atosiban guides
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