[Inhibition of ovulation with 35 micrograms of ethinyl estradiol and 2 mg of cyproterone acetate (Diane 35)].

In the study reported here the ovulation inhibition dose for cyproterone acetate was determined. Experiments showed that the ovulation inhibition dose is 1 mg of cyproterone acetate, administered daily. Results proved that the cyproterone acetate dose cannot be reduced when cyproterone acetate is combined with ethinyl estradiol. However, the objective of this study was to determine whether it is possible to reduce the estrogen dose to 35 micrograms when the common combination of 2 mg cyproterone acetate and ethinyl estradiol is being used. After a control menstruation cycle, 2 mg cyproterone acetate and 35 micrograms ethinyl estradiol were administered daily to six women with normal menstruation. Drug administration began on Day 5 and ended on Day 25. During the control cycle, the first treatment cycle, and the third treatment cycle, LH, FSH, 17 beta estradiol, progesterone, testosterone, prolactin, and SHGB were examined daily. Cervix score and karyopyknosis index were determined at the same time. In addition, antithrombin III was examined during the control cycle and during the third treatment cycle. Present results show that ovulation inhibition is possible with dose reduction of ethinyl estradiol to 35 micrograms, combined with 2 mg of cyproterone acetate. Increase in SHBG and reduction in testosterone serum level point to an additional antiandrogenic effect of cyproterone acetate, aside from its cellular effect. The combined preparation discussed here does not bring about any changes in antithrombin III values. Results permit the conclusion that ovulation inhibition is insured with a reduction of the daily estrogen dose from 50 micrograms to 35 micrograms.