Effects of cetrorelix,a GnRH-receptor antagonist,on gonadal axis in women with functional hypothalamic amenorrhea

Background.?Gonadotropin Releasing Hormone (GnRH) antagonists (GnRHa) suppress gonadotropin and sex-steroid secretion. In normal women, acute GnRHa administration induces inhibitory effect on pituitary-gonadal axis, followed by Luteinizing Hormone (LH) rebound. Functional hypothalamic amenorrhea (HA) is characterised by impaired gonadotropin secretion and hypogonadism secondary to blunted GnRH pulsatility.

Methods.?We studied the effects of a GnRHa, cetrorelix (CTX 3.0?mg), in six women with HA (age 30.7?±?3.2 years; BMI 21.5?±?1.7 kg/m²) and six control subjects (CS, 28.2?±?0.6 years; 22.6?±?0.9 kg/m²) on LH, Follicle-Stimulating Hormone (FSH) and oestradiol levels over 4?h (08.00–12.00 am) before, +24?h and +96?h after CTX; LH, FSH, and oestradiol were also evaluated at +6, +8, +12, +48, +72?h after CTX.

Results.?CS: CTX reduced (p?p?p?p?Conclusions.?One single CTX dose still modulates gonadotropin secretion in HA. Its ‘paradoxical’ stimulatory effect on gonadotropins needs to be verified after prolonged administration.