Cetrorelix 5mg

Cetrorelix is a man-made decapeptide that exhibits antagonistic properties against gonadotropin-releasing hormone (GnRH). GnRH is responsible for stimulating the production and release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the gonadotrophic cells in the anterior pituitary gland.
During the middle of the menstrual cycle, there is a positive feedback loop involving estradiol (E2), which amplifies GnRH release, leading to an LH surge. This surge in LH triggers the ovulation of the dominant follicle, restarts oocyte meiosis, and initiates luteinization, as evidenced by increasing progesterone levels.

Cetrorelix competes with natural GnRH for binding to membrane receptors on pituitary cells, effectively regulating the release of LH and FSH in a manner that depends on the dosage administered.

Mechanism of action.

Cetrorelix attaches to the receptor for gonadotropin-releasing hormone, functioning as a strong inhibitor of gonadotropin secretion. It competes with the naturally occurring GnRH for binding to the membrane receptors found on pituitary cells, effectively regulating the release of LH and FSH in a manner that depends on the dosage administered.

The impact of Cetrotide on LH and FSH is temporary and can be reversed upon discontinuation of treatment. In women, Cetrotide dose-dependently postpones the LH surge, and consequently, ovulation. FSH levels remain unaffected at the prescribed doses during controlled ovarian stimulation. After a single 3 mg dose of Cetrotide, its effects last for a minimum of 4 days. Administering Cetrotide at a dosage of 0.25 mg every 24 hours has been demonstrated to sustain this effect.

Absorption

Cetrotide is quickly absorbed when administered via subcutaneous injection, with peak plasma concentrations typically reached within one to two hours post-administration. In healthy female subjects, the average absolute bioavailability of Cetrotide after subcutaneous injection is approximately 85%.

Contraindications

Cetrorelix should not be used in cases of severe renal impairment. It is not intended for women aged 65 years or older. The use of Cetrorelix is not advised for women with severe allergic conditions and should be approached with caution in those with active allergies or a history of allergies.