The LH and FSH responses to LH-releasing hormone (LH-RH) in girls with true precocious puberty treated with cyproterone acetate.

Ten girls with precocious puberty ranging in age from 7 to 10 7/12 years who were treated with oral cyproterone acetate on a long term basis, were subjected to LH-RH tests, prior to and 3 to 16 months after the institution of therapy. Cyproterone acetate was given in doses from 60 to 153 mg/m2, which proved to be clinically effective, as evidenced by the slowing down of sexual maturation. The basal levels of LH were found to be unaffected by therapy and corresponded to the pubertal stages of the individual girls. The peak increment of LH after LH-RH stimulation was markedly suppressed by the therapy. FSH secretion and its responsiveness to LH-RH was not affected by cyprotereone acetate. The basal levels of FSH were higher during therapy than before, but the peak FSH increment remained the same. An escape phenomenon in the LH peak response was evident in 2 patients upon retesting after prolonged therapy. It is possible that the antigonadotrophic action of cyproterone acetate is due to its progestational nature.