Cetrorelix Acetate Used As GnRH Antagoniststo to Prevent Premature Ovulation CAS NO.120287-85-6

Cetrorelix belongs to the class of medications called GnRH antagonists. Cetrorelix is used to prevent premature ovulation in women undergoing ovarian stimulation. It blocks the effects of gonadotropin-releasing hormone (GnRH). GnRH controls the secretion of another hormone, called luteinizing hormone (LH), a hormone that starts ovulation (release of an egg) during the menstrual cycle. Cetrorelix allows the release of an egg to be controlled so it is released at the best time for pregnancy to occur.

Cetrorelix is marketed for use in in-vitro fertilization in all countries except Japan, where it is marketed by Shionogi and Nippon Kayaku. Aeterna Zentaris receives royalties on these sales and retains rights to develop cetrorelix for other indications. In IVF use it is injected daily after follicle stimulation has been initiated and evidence of follicle maturation is approaching; given daily it prevents an endogenous LH surge that would trigger an untimely ovulation prior to the hCG administration by the treating physician. As an alternative to the GnRH antagonist, also a GnRH agonist could be given, but agonist have to be started earlier to overcome the agonistic effect. Cetrorelix can be mixed with follitropin alpha without compromising their reported safety and efficacy.