A comparative study of clomiphene and epimestrol on plasma progesterone, CBG, TBG and SHBG, and salivary progesterone levels.

The plasma levels of CBG, TBG, SHBG and progesterone, and salivary progesterone levels were measured in eight young ovulatory volunteers. After the control cycle four subjects received 50 mg/day of Clomiphene from days 5 to 9 of the first treatment cycle, and 10 mg/day of Epimestrol from days 5 to 15 of the second treatment cycle. The other four subjects received the treatments in reverse order. Between the two treatments there was one cycle without medication as a "wash-out" period. Plasma and saliva samples were obtained on days +6, +8 and +10 (day of LH peak was denoted by 0), always between 08.00 and 09.00 h. Statistical evaluation was done by means of an analysis of variance (ANOVA), and correlation coefficients were also calculated. Evaluation of data on effects of Clomiphene and Epimestrol on the plasma levels of CBG and salivary progesterone showed that Clomiphene induced a highly significant rise (p less than 0.001) in the CBG levels and decrease (p less than 0.001) in salivary progesterone levels, while no changes were seen following administration of Epimestrol. Both Clomiphene and Epimestrol treatments led towards higher plasma progesterone levels, those following Clomiphene administration being higher. Neither treatment induced significant changes in TBG or SHBG levels. It is concluded that Clomiphene induces significant elevations of CBG and decrease in salivary progesterone, which is thought to reflect the free progesterone fraction and may have significance in relation to a discrepancy between the ovulation and pregnancy rates following Clomiphene therapy.