VARIATIONS IN PITUITARY-GONADAL SUPPRESSION DURING INTRANASAL BUSERELIN AND INTRAMUSCULAR DEPOT-TRIPTORELIN THERAPY FOR CENTRAL PRECOCIOUS PUBERTY

This study evaluated pubertal development, growth and pituitary-gonada l suppression in 21 patients with central precocious puberty treated w ith buserelin intranasally and switched after a mean of 2.1 yr to depo t-triptorelin given im for I year. Arrest or regression of puberty was observed in 12 patients while progression of puberty during therapy w as seen in 9 patients (6 on buserelin, 2 on triptorelin and 1 on both therapies). The increment in serum LH and FSH concentrations after sc injection of short-acting triptorelin was greater on buserelin than on triptorelin therapy, particularly in patients with evidence of progre ssion of puberty. Height velocity during therapy showed a reduction wh ich paralleled the decelerating phase of the normal pubertal growth sp urt. The rate of bone maturation during therapy was inversely related to pretreatment bone age. Predicted final height showed marked individ ual variations which were inversely related to predicted adult height before therapy. These data indicate that differences in the nature and route of administration of Gn-RH agonist therapy for central precocio us puberty can be of importance for inhibition of pituitary gonadotrop in secretion and development of secondary sex characteristics. Height velocity and bone maturation are age-related and the change in predict ed adult height depends on pretreatment level.