<prompt> True about atosiban is?Is an oxytocin receptor antagonistIs an progesterone receptor antagonistIs least effective in inhibiting preterm uterine ContractionsIs a anti-tocolytic drug  <response>: Atosiban is a peptide analog of oxytocin that acts as an antagonist at the oxytocin receptors. It is a tocolytic. It suppress uterine contractions and postpones preterm delivery. Ref.Essentials of medical pharmacology TD Tripathi 6th edition page no.333. 