barusiban and relcovaptan

Embryo transfer, the final stage of IVF/embryo transfer (IVF/ET) treatment, independently influences treatment outcome.Successful embryo implantation following embryo transfer, among other factors, is also dependant on uterine receptivity.Uterine contractile activity may adversely affect the implantation. Although increased contractions have been found in approximately 30% of patients undergoing embryo transfer, to date it has not been a subject to any diagnosis or therapy. Pharmacological tocolytics may be expected to improve pregnancy rates; however, targeting uterine adrenergic receptors, calcium channels or prostaglandin synthesis has since proven ineffective. The novel class of drugs which could be the most useful in this indication is oxytocin antagonists. In animal models, oxytocin significantly reduced embryo implantation rates, and this was reversed by an oxytocin antagonist. In humans, peptidyl oxytocin and mixed vasopressin V1A/oxytocin antagonists have been found to significantly reduce uterine contractions in egg donors undergoing mock embryo transfer. It has further been demonstrated that the vasopressin V1A/oxytocin receptor antagonist atosiban can improve pregnancy success in patients with recurrent IVF failures. This article reviews the uterine oxytocin/vasopressin V1A receptor systems and their potential influence on embryo implantation. It is suggested that the clinical application of oxytocin antagonists might improve results of IVF/ET treatment.

Topics: Animals; Antidiuretic Hormone Receptor Antagonists; Embryo Implantation; Female; Humans; Indoles; Infertility; Oligopeptides; Oxytocin; Pregnancy; Pyrrolidines; Receptors, Oxytocin; Reproductive Techniques, Assisted; Tocolytic Agents; Uterine Contraction; Vasopressins; Vasotocin

Preterm birth, the leading cause of neonatal morbidity and mortality, is estimated at incidence of 12.7% of all births, which has not decreased over the last four decades despite intensive antenatal care programs aimed at high-risk groups, the widespread use of tocolytics, and a series of other preventive and therapeutic interventions. Oxytocin antagonists, namely atosiban, represent an appealing choice that seems to be effective with apparently fewer side effects than the traditional tocolytics. This article reviews the available literature on the pharmacokinetics, mode of administration, and clinical utility of oxytocin antagonists for acute and maintenance tocolysis with special emphasis on its safety profile.

Topics: Female; Hormone Antagonists; Humans; Indoles; Nifedipine; Oligopeptides; Oxytocin; Premature Birth; Pyrrolidines; Sympathomimetics; Tocolytic Agents; Vasotocin