Prescribing Notes

Growth disorders

The synthetic growth hormone somatropin is identical in structure to endogenous human growth hormone and indicated for children whose endogenous growth hormone output is insufficient to enable normal stature to be attained. It may also be used in gonadal dysgenesis, Turner syndrome and for growth disturbance in prepubertal children with chronic renal insufficiency. In adults, it can be used for replacement therapy in growth hormone deficiency. The deficiency normally develops following treatment of a hypothalamic or pituitary adenoma. Symptoms include raised serum cholesterol levels, decreased bone mineral density and disturbed renal function. Patients should also receive adequate replacement therapy for other pituitary hormone deficiencies. Somatrogon is a long-acting recombinant growth hormone comprising the amino acid sequence of human growth hormone and three copies of the carboxy-terminal peptide derived from human chorionic gonadotropin. It is injected weekly.

The acromegaly treatments lanreotide, octreotide and pasireotide are analogues of somatostatin that reduce circulating levels of growth hormone improving the incidence and severity of headache, sweating and arthralgia. Octreotide has a short half-life and if administered by sc inj it has to be given three times per day. Alternatively, octreotide in the form of microspheres can be injected im at 4-week intervals. Lanreotide has a longer half-life than octreotide because it is more enzymatically stable. When formulated with a copolymer there is a significant extension to lanreotide''s duration of action, allowing im inj every 7 to 14 days. Pasireotide is administered by im inj every 4 weeks. Pegvisomant is a genetically modified growth hormone antagonist that reduces IGF-I in acromegalic patients by blocking growth hormone binding to its receptor sites. Bromocriptine is a dopamine agonist, highly effective in suppressing elevated serum prolactin. It is used to prevent puerperal lactation and treat galactorrhoea. It can be effective in prolactinoma and can reduce levels of growth hormone in acromegaly.