EFFECTS OF CLOMIPHENE CITRATE ON PITUITARY LUTEINIZING-HORMONE AND FOLLICLE-STIMULATING-HORMONE RELEASE IN WOMEN BEFORE AND AFTER TREATMENT WITH ETHINYL ESTRADIOL

Objective: To evaluate the effects of clomiphene citrate (CC) on pituitary luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release in hypoestrogenic women and in the same women after treatment with ethinyl estradiol (EE2). Design: The study was of a prospective nature and was conducted on selected patients. Setting: Volunteer women were studied in a tertiary care public hospital. Patients: The 10 patients studied were selected on the basis of hypogonadal status (menopause, premature ovarian failure, or gonadal dysgenesis and Turner phenotype) and no hormonal treatment. Interventions: Gonadotropin-releasing hormone (GnRH) was continually infused at the dose of 0.2-mu-g/min for 4 hours before and after the use of CC and/or EE2. Main Outcome Measure: The study was performed with the objective of determining the effect of estrogen (E) levels on the action of CC on in vivo gonadotropin release. Results: In the presence of hypoestrogenic conditions, CC had no pituitary action. However, after EE2 treatment CC promoted greater FSH release and a significant inhibition of LH release from the pituitary. Conclusion: Clomiphene citrate needs a basal E level to be able to act on the pituitary. In normoestrogenic states and under GnRH stimulation, CC preferentially promotes FSH release while presenting a predominantly inhibitory effect on LH release.