Gonadotrope cells produce luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in the pituitary gland. Natural gonadotropin-releasing hormone (GnRH) binds with receptors on gonadotrope cells. This binding results in the production and release of LH and FSH and the production of new GnRH receptors on the gonadotropes. Ganirelix Acetate Injection acts by blocking the natural GnRH from binding to GnRH receptors, thereby inducing a rapid, reversible suppression of gonadotropin secretion. When GnRH antagonists bind to the GnRH receptor, pituitary FSH and LH are not released. The suppression of LH is more pronounced than the suppression of FSH. When a patient stops using Ganirelix Acetate Injection, pituitary LH and FSH levels are fully recovered within 48 hours.
 
In patients undergoing Assisted Reproductive Technologies, such as IVF, these attributes of Ganirelix Acetate Injection translate into an innovative means of inhibiting premature LH surges. A large increase in GnRH release results in an LH surge at mid-cycle. This mid-cycle LH surge initiates ovulation, the release of immature eggs.

Compared to treatment with GnRH agonists, the course of treatment with Ganirelix Acetate Injection is relatively short. GnRH agonists must be administered beginning anywhere from 10 to 14 days sooner than treatment with GnRH antagonists and continue through the gonadotropin stimulation cycle, often in excess of 20 days.

Continued use of GnRH agonists over a period of weeks to inhibit LH release can cause overstimulation. In scientific terms, this is called "desensitization", which means that the patient fails to respond after continued stimulation. Side effects of GnRH agonists such as the clinical signs of menopause (hot flashes and sleeping disorders) are frequently reported.

Ganirelix Acetate Injection is available in disposable, sterile, pre-filled syringes containing 250 micrograms of ganirelix acetate. Unlike older treatments on the market, this medication can be self-injected using the supplied syringe for injection just under the skin (subcutaneous).

Ganirelix Acetate Injection is the only LH surge inhibitor packaged in a ready-to-inject syringe, so mixing isn't required.

For the Instructional Quick Guide to Ganirelix Acetate Injection, click here.