We describe a 12-y-old boy with excessive
growth hormone and
prolactin secretion presumably due to diffuse somatotroph
hyperplasia. Until mid-puberty, his growth rate was under reasonable control, with high-dose
octreotide injections every 8 h combined with a
dopamine agonist. As his growth velocity started to increase, the efficacy of continuous s.c.
octreotide infusion on GH secretion was tested. Similar total daily doses (600 microg) of
octreotide were administered either by incremental s.c.
injections at 8 h intervals, or by continuous s.c. infusion, two-thirds of the amount during night-time to control the presumed high nocturnal
growth hormone (GH) peaks of the pubertal growth spurt. An overnight GH profile showed inadequate suppression of GH levels by incremental
injections, while continuous s.c. infusion efficiently brought down the GH secretion. Another
somatostatin analogue,
lanreotide as a single depot injection was not effective. A 6-mo trial on the s.c. infusion regimen significantly reduced
growth hormone secretion (as judged by
IGF-I and IGFBP3 concentrations), and normalized growth velocity overcoming the pubertal growth spurt. It also caused a decrease in the pituitary size in magnetic resonance images. We conclude that the efficacy of
octreotide infusion in suppressing GH secretion is superior to incremental
injections with the same dose.