Hormonal Agents · Progesterone and Progestins
Driguez PD et al., 1999 · Clin Ther
This review sought to examine the rationale for selecting an oral micronized progesterone formulation rather than a synthetic progestin for some of the main indications for progestogens. Unopposed estrogen use is associated with a high risk (relative risk, 2.1 to 5.7) of endometrial hyperplasia and adenocarcinoma, and it has been understood for some time that a progestogen must be added for at least 10 to 14 days per month to prevent these effects. However, the most commonly used synthetic progestins, norethisterone and medroxyprogesterone acetate, have been associated with metabolic and vascular side effects (eg, suppression of the vasodilating effect of estrogens) in both experimental and human controlled studies. All comparative studies to date conclude that the side effects of synthetic progestins can be minimized or eliminated through the use of natural progesterone, which is identical to the steroid produced by the corpus luteum. The inconvenience associated with the use of injectable, rectal, or vaginal formulations of natural progesterone can be circumvented by using orally administered micronized progesterone. The bioavailability of micronized progesterone is similar to that of other natural steroids, and interindividual and intraindividual variability of area under the curve is similar to that seen with synthetic progestins. A clear dose-ranging effect has been demonstrated, and long-term protection of the endometrium has been established. Micronized progesterone has been used widely in Europe since 1980 at dosages ranging from 300 mg/d (taken at bedtime) 10 days a month for women wishing regular monthly bleeding to 200 mg 14 days a month or 100 mg 25 days a month for women willing to remain amenorrheic. This therapy is well tolerated, with the only specific side effect being mild and transient drowsiness, an effect minimized by taking the drug at bedtime. The prospective, comparative Postmenopausal Estrogens/Progestin Intervention trial has recommended oral micronized progesterone as the first choice for opposing estrogen therapy in nonhysterectomized postmenopausal women.
Breast Health · Breast Cancer Risk
Foidart JM et al., 1998 · Fertil Steril
To study the effects of estradiol and progesterone on the proliferation of normal human breast epithelial cells in vivo. Double-blind randomized study. Departments of gynecology and of cell biology at a university hospital. PATIENT(S): Forty postmenopausal women with untreated menopause and documented plasma FSH levels of >30 mIU/mL and estradiol levels of <20 pg/mL. INTERVENTION(S): Daily topical application to both breasts of a gel containing a placebo, estradiol, progesterone, or a combination of estradiol and progesterone during the 14 days preceding esthetic breast surgery or excision of a benign lesion. MAIN OUTCOME MEASURE(S): Plasma and breast tissue concentrations of estradiol and progesterone. Epithelial cell cycles were evaluated in normal breast tissue by counting mitoses and performing quantitative proliferating cell nuclear antigen immunolabeling analyses. RESULT(S): Increasing the estradiol concentration enhanced the number of cycling epithelial cells, whereas increasing the progesterone concentration significantly limited the number of cycling epithelial cells. CONCLUSION(S): Exposure to progesterone for 14 days reduced the estradiol-induced proliferation of normal breast epithelial cells in vivo.
Breast Health · Breast Cancer Risk
Chang KJ et al., 1995 · Fertil Steril
To study the effect of E2 and P on the epithelial cell cycle of normal human breast in vivo. Double-blind, randomized study. Topical application to the breast of a gel containing either a placebo, E2, P, or a combination of E2 and P, daily, during the 10 to 13 days preceding breast surgery. Forty premenopausal women undergoing breast surgery for the removal of a lump. MAIN OUTCOME MEASURES. Plasma and breast tissue concentrations of E2 and P. Epithelial cell cycle evaluated in normal breast tissue areas by counting mitoses and proliferating cell nuclear antigen immunostaining quantitative analyses. Increased E2 concentration increases the number of cycling epithelial cells. Increased P concentration significantly decreases the number of cycling epithelial cells. Exposure to P for 10 to 13 days reduces E2-induced proliferation of normal breast epithelial cells in vivo.
Neuroendocrinology · Hypothalamic Amenorrhea
Gompel A et al., 1988 · Hum Reprod
Pulsatile administration of gonadotrophin releasing hormone (GnRH) is a very effective treatment for induction of ovulation in hypothalamic amenorrhoea (HA). Thirty-seven women have been treated for a total of 117 cycles which resulted in 42 pregnancies--four treatment failures occurred. If these cycles are excluded, the 42 pregnancies were obtained within 2.3 cycles. One twin pregnancy occurred and no hyperstimulation was observed. The treatment was administered intravenously with a dosage schedule based on the grading of HA. We concluded that pulsatile GnRH was safe and very successful in induction of pregnancy in HA. Other indications (polycystic ovary syndrome and luteal phase defect) remain much less suitable for this treatment.
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