LH and FSH response to synthetic LHRH after consecutive administration of clomiphene citrate in normal males.

LHRH tests (100 mug iv) were performed in 11 normal male volunteers before and after administration of 100 mg clomiphene citrate per os for 7 days. Serum FSH, both pre and post LHRH levels (peak value and area under response curve) were significantly increased (P less than 0.01) by clomiphene citrate, while the maximum increments of FSH above baseline (deltaFSH) and area under response curve from basal level (deltaarea) were unchanged. On the other hand, basal serum LH levels increased significantly (P less than 0.005), post LHRH levels did not change by clomiphene citrate, whereas the increments after LHRH administration (both deltaLH and deltaarea) decreased significantly (P less than 0.05) on the second LHRH test. Basal levels of testosterone increased following clomiphene citrate treatment (P less than 0.005). The increased testosterone is considered to suppress the effect of LHRH on LH secretion.