Contraception
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The efficacy of a low dose of mifepristone, 5 mg/day for the first 15 days of the menstrual cycle, followed by medroxy-progesterone acetate (MPA), 10 mg/day for the next 13 days, for inhibiting ovulation was assessed in ten volunteers who were treated for three successive cycles. Hormonal determinations in blood and urine samples, ovarian ultrasonography and an endometrial biopsy taken on day 21-24 of the third treatment cycle were used to monitor the cycles. Ovulation was confirmed in 11 of the 30 treated cycles and, in these 11, the LH peak and follicular rupture occurred during MPA treatment periods. ⋯ Progestin administration induced secretory changes in the endometrium, but irregular or delayed development was found. Regular withdrawal bleeding occurred in all subjects. These data indicate that the sequential regimen can suppress ovulation while maintaining regular bleeding but increased efficacy is needed for phase II clinical trials.
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Comparative Study
Inhibition of ovulation by progestin analogs (agonists vs antagonists): preliminary evidence for different sites and mechanisms of actions.
Continuous administration of the antiprogesterone RU486 inhibits ovulation in women and in monkeys; in this regard RU486 may act as a progestin agonist rather than as an antagonist. We compared the site(s) and mechanism(s) of RU486-induced ovulation inhibition with those of levonorgestrel (LNG). Six regularly menstruating cynomolgus monkeys each received placebo, RU486 (1 mg/kg/d) or LNG (2 g/kg/d) i.m. between days (cd) 2-22 of three separate menstrual cycles. ⋯ The pituitary does not appear to be the major site of action(s) of RU486 or LNG. Thus, the differential mechanisms of ovulation inhibition by RU486 and LNG seem to result from lesser intraovarian impact of RU486 as well as dissimilar influences on tonic gonadotropin secretory levels. We conclude that when inhibiting ovulation, RU486 does not act as a progestin agonist, but rather, functions through a hypothalamic mechanism(s), which might be unique to RU486 as a progesterone antagonist.
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The effect of modern low-dose oral contraceptives (OCs) on the levels of follicle stimulating hormone (FSH) and luteinizing hormone (LH) in young, health, nulligravid women was studied in two independent samples. Elevated FSH levels were seen in former OC users compared with never users regardless of menstrual cycle phase. The increase in FSH levels seemed to peak one year after cessation of OC use. ⋯ The difference in FSH concentrations was very small. Single blood samples were obtained from the subjects at each time point even though it is recognized that gonadotropin secretion is pulsatile. These results must be regarded as preliminary and unconfirmed due to small sample size.
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Clinical Trial
Effect of levonorgestrel-releasing intrauterine device on hormonal profile and menstrual pattern after long-term use.
In the present study 14 women after 6 years' use of levonorgestrel-releasing IUD were investigated for the changes of LH, progesterone (P), estradiol (E2), prolactin (PRL) and serum binding globulin (SHBG) in relation to the levonorgestrel levels throughout a segment of 26-40 days with the aim of comparing the hormonal profiles with those during the first year of use of Lng-IUD. Ultrasound scanning was used to follow the development of follicles along with the RIA measurement of hormones. The results of serum LH, P and E2 showed ovulation in 11 cases with either normal menstrual cycles (5 cases), prolonged or irregular cycles (4 cases) or with amenorrhea for 2-3 years (2 cases). ⋯ The persistent enlargement of follicles coincided with high levels of E2. After 6 years of use, the serum levels of levonorgestrel were still maintained at mean levels of 314.26 pmol/L and 470.63 pmol/L in the ovulatory and anovulatory groups, respectively. It is concluded that over two-thirds of the cases have ovulatory cycles after long-term use of Lng-IUD; the contraceptive effect is mainly due to its local action on the endometrium, with much less effect on the ovarian function.
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Randomized Controlled Trial Clinical Trial
Neutralizing pH of lidocaine reduces pain during Norplant system insertion procedure.
The acidity of lidocaine used as a local anesthetic during the insertion of Norplant System capsules can cause patient discomfort. Buffering lidocaine with sodium bicarbonate significantly reduced pain scores reported by 46 women who participated in this randomized, double-blind study. Derived from a pain scale of 1 to 10, the mean difference in reported pain scores with and without buffering was 1.17 (P = 0.0098) with women using themselves as controls, for an average reduction in pain of 29%. Because this added step minimized patient discomfort, it might make the Norplant System a more attractive option for women apprehensive about insertion pain.