Research Article|Articles in Press

Ganirelix and the prevention of premature LH surges

Open AccessPublished:February 23, 2023DOI:
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      Ganirelix is a GnRH antagonist with high antagonistic activity that blocks the GnRH receptor by competitive binding. A daily dose of 0.25 mg ganirelix was selected following a Phase 2 study as it was the minimal, effective daily dose to prevent premature LH surges, and yielded the highest ongoing pregnancy rate per started cycle. Following subcutaneous administration, ganirelix is rapidly absorbed, reaching peak levels 1 to 2 hours (tmax) and has a high absolute bioavailability (>90%). Prospective, comparative studies have demonstrated the advantages of GnRH antagonist over long GnRH agonists treatment in assisted reproduction, including: (i) the immediate reversibility of drug effects; (ii) a requirement for less FSH; (iii) a shortened duration of stimulation; (iv) a reduced incidence of ovarian hyperstimulation syndrome (OHSS); and (v) reduced patient burden. Combined analyses concluded that in the general IVF population, there is a slightly lower ongoing pregnancy rate, but also a lower risk of OHSS that is largely eliminated when considering triggering with GnRH agonist instead of hCG. Regardless of all research, it is still not fully elucidated why the long GnRH agonist protocol has a trend for higher pregnancy rates following fresh transfer of the same number of good quality embryos.