Atosiban

Atosiban (trade names Tractocile, Antocin, Atosiban SUN) is an inhibitor of the hormones oxytocin and vasopressin. It is used as an intravenous medication as a labour repressant (tocolytic) to halt premature labor. It was developed by Ferring Pharmaceuticals in Sweden and first reported in the literature in 1985. Originally marketed by Ferring Pharmaceuticals, it is licensed in proprietary and generic forms for the delay of imminent preterm birth in pregnant adult women. In India it is marketed under the brand name Tosiban by Zuventus healthcare ltd. Atosiban (trade names Tractocile, Antocin, Atosiban SUN) is an inhibitor of the hormones oxytocin and vasopressin. It is used as an intravenous medication as a labour repressant (tocolytic) to halt premature labor. It was developed by Ferring Pharmaceuticals in Sweden and first reported in the literature in 1985. Originally marketed by Ferring Pharmaceuticals, it is licensed in proprietary and generic forms for the delay of imminent preterm birth in pregnant adult women. In India it is marketed under the brand name Tosiban by Zuventus healthcare ltd. Atosiban is a nonapeptide, desamino-oxytocin analogue, and a competitive vasopressin/oxytocin receptor antagonist (VOTra). Atosiban inhibits the oxytocin-mediated release of inositol trisphosphate from the myometrial cell membrane. As a result, reduced release of intracellular, stored calcium from the sarcoplasmic reticulum of myometrial cells and reduced influx of Ca2+ from the extracellular space through voltage-gated channels occur. In addition, atosiban suppresses oxytocin-mediated release of PGE and PGF from the decidua. In human preterm labour, atosiban, at the recommended dosage, antagonises uterine contractions and induces uterine quiescence. The onset of uterus relaxation following atosiban is rapid, uterine contractions being significantly reduced within 10 minutes to achieve stable uterine quiescence. Atosiban is indicated to delay imminent preterm birth in pregnant adult women with: Atosiban is useful in improving the pregnancy outcome of in vitro fertilization-embryo transfer (IVF-ET) in patients with repeated implantation failure. The pregnancy rate improved from zero to 43.7%. First- and second-trimester bleeding was more prevalent in ART than in spontaneous pregnancies. From 2004 to 2010, 33 first-trimester pregnancies with vaginal bleeding after ART with evident uterine contractions, when using atosiban and/or ritodrine, no preterm delivery occurred before 30 weeks. In a recent meta-analysis, nifedipine is superior to β2 adrenergic receptor agonists and magnesium sulfate for tocolysis in women with preterm labor (20–36 weeks), but it has been assigned to pregnancy category C by the U.S. Food and Drug Administration, so is not recommended before 20 weeks, or in the first trimester. Recent reports support the use of atosiban, even at very early pregnancy, to decrease the frequency of uterine contractions to enhance success of pregnancy. Following the launch of Atosiban in 2000, the calculated cumulative patient exposure to Atosiban (January 2000 to December 2005) is estimated as 156,468 treatment cycles. To date, routine monitoring of drug safety has revealed no major safety issues. Atosiban was approved in the European Union in January 2000 and launched in the European Union in April 2000. As of June 2007 atosiban is approved in 67 countries, excluding the USA and Japan. It is understood that Ferring does not expect to seek approval for atosiban in the USA or Japan, focusing instead on development of new compounds for use in Spontaneous Preterm Labor. The fact that Tractocile® (atosiban) only had a short duration before it was out of patent that the parent drug company decided not to pursue licensing in the USA.