新型长效避孕器——硅橡胶缓释避孕环的研究

用合成硅橡胶材料制成的新型缓释避孕环,内含甲地孕酮200毫克,其外径为40毫米。经体外测试,药物的释放量每天约100微克左右。本环临床试用2470例,共16124妇女月经周期。由于药物能持续、缓慢释放,连续使用一年,仍保持避孕效果。现已有522例连续使用一年以上,受孕率为2.15%(按妇女年计算)。由于部分妇女阴道肌肉松弛,环易脱落,脱落率为2.15%。使用甲地孕酮硅橡胶避孕环一年以上的妇女,经医师检查未发现阴道粘膜刺激及红肿现象。主要副反应为突破性出血,突血率近7%。月经不正常情况主要发生在最初三个月,以后逐步好转。经临床及实验室研究,本环的作用不抑制排卵,而对宫颈粘液有较明显的改变,不利于精子穿透;子宫内膜虽仍属分泌期,但发育较差,不利于孕卵着床;对下丘脑—垂体—卵巢轴影响较小,且又具有较好的避孕效果。

STUDIES ON MEGESTROL ACETATE INTRAVAGINAI SILASTIC RING AS A NEW CONTRACEPTIVE DEVICE

The intravaginal ring was made by synthetic silicon rubber tube containing 200 mg of solid megestrol acetate,with an outer diameter of 40mm.The in vitroreleasing test showed it had a release rate of approximately 100 μg per day.The clinical study group consisted of 2,470 volunteer women and the totaltreatment cycles were 16,124 women months.The ring sustainedly releasedsteroid and could provide contraceptive effeciency for one year.There were522 subjects up to present who had been using a ring for one year.The over allpregnancy rate was 2.15 per cent due to less muscular tension of vagina,no ir-ritation and erosion of vaginal mucosa was observed after the insertion of the ringfor one year.The main side effect was break through bleeding,accounting fornearly 7 per cent of treatment cycles.Uncomfortable sense usually occurredwithin the first three month of treatment.There was no apparent suppression of ovulation in the cases of using the meges-trol acetate intravaginal rings,according to our limited cnical and laboratory studies.There was obvious change in mucus,which was unfavorable for thepenetration of sperm.The majority of the cases had secretory endometrium ofdeficient glandular secretion which was unfavorable for nidation.In other words,sustained release of lower dosage of megestrol acetate from the intravaginal ringgave little disturbance to hypothalamus-pituitary-ovary axis,but it provided asatisfactory contraceptive effect.