Assessment of depot leuprolide acetate dose-adequacy for central precocious puberty

The development of GnRH analogs (GnRHa) has made it possible to treat children with central precocious puberty (CPP). This treatment may prevent adult short stature due to premature epiphyseal fusion. Achievement of this goal, however, is dependent upon adequate suppression of gonadal steroid production as a result of GnRHa-induced pituitary desensitization and decreased gonadotropin release. A depot formulation of a GnRHa [leuprolide acetate (dLA)] is being used by many clinicians for the treatment of CPP, but studies to establish the optimal dose of dLA have not been performed. In this study we evaluated the effectiveness of dLA (7.5 mg, im, every 4 weeks). Six children (7-10 yr old) with CPP treated with dLA were assessed clinically and divided into two groups: A (incompletely suppressed) and B (well suppressed). Each group had overnight blood sampling and a GnRH stimulation test the following morning. LH pulses were analyzed and compared to 11 normal prepubertal children. Mean LH concentration, LH curve area, LH pulse frequency, and mean LH pulse amplitude were significantly greater (P less than 0.03) in group A than in group B or the normal prepubertal children. There was no significant difference among the three groups in GnRH-stimulated peak LH release. These results indicate that dLA (7.5 mg, im, every 4 weeks) does not produce complete desensitization in all children with CPP and suggest that overnight monitoring of LH release is more sensitive than GnRH stimulation testing for the assessment of dLA dose adequacy.