Menotropin

Menotropin

Menotropin is extracted from the urine of postmenopausal women (Lunenfeld, 2004). Early preparations contained varying levels of FSH, LH, and human chorionic gonadotropin (hCG). Currently, new purification techniques resulted in FSH and LH activities standardized at 75 IU for each type of gonadotropin (ASRM, 2008). Human menopausal gonadotropin (hMG) have both FSH and LH activity, but the latter is primarily derived from the hCG component in postmenopausal urine, which is concentrated during purification (Lunenfeld, 2004). Occasionally, hCG is added to induce the desired level of LH-like biological activity (Lunenfeld, 2004). Currently, hMG are commercially available at FSH:LH ratio of 1:1.

FSH is fundamental for follicular recruitment in the first stages of folliculogenesis, while LH is important for ovarian steroidogenesis and is involved in physiological events that promote the growth of an appropriate preovulatory follicle in the last stages of folliculogenesis.

In view of that, menotropin, having a double activity (FSH and LH), induces the growth and the development of ovarian follicles as well as the gonadic steroids in women with primitive ovarian deficiency. After an intramuscular or subcutaneous administration, the menotropin is excreted mainly by the kidney.

Furthermore, according with LH action in steroidogenesis strengthening, estradiol levels associated with menotropin treatment are higher than those associated with the one based on recombinant FSH (r-hFSH) in IVF cycles. This must be considered during stimulation. It is available in the pharmaceutical form of solution or powder with dosages of: 75 IU, 600 IU and 1200 IU.

Due to individual variability of ovarian response to the exogenous gonadotropins treatment, it is not possible to define a uniform dosing schedule. The recommended initial dose is usually 150–225 IU per day for at least the first 5 days, but it could be modified during the stimulation on the base of estradiol levels or follicles growth. Generally, the maximum dose should not exceed 450 IU per day and for no more than 20 days.