Medical Therapy

The aim here is to normalize GH and IGF-1 levels and ideally control tumor size and limit development and progression of co-morbid conditions.

There are 3 classes of drugs used to suppress GH and IGF-1 levels:

I. Somatostatin Analogues - The drugs in this class reduce GH secretion by mimicking the action of naturally occurring somatostatin, the inhibitor of GH secretion from the pituitary.

Octreotide (Sandostatin®)

This is the most commonly used pharmaceutical agent to control GH secretion from the pituitary tumor. Octreotide is an analogue of the naturally occurring hormone, Somatostatin. Octreotide works through Somatostatin receptors (2, 5) on the Somatotroph cells within the pituitary tumor. This results in a reduction in the amount of GH secretion from the tumor cells resulting in lowered levels of the GH and IGF-1 in the circulation. Administration of Octreotide is by daily subcutaneous injection.

Newer, long acting somatostatin analogues e.g. Sandostatin LAR® and Lanreotide SR are administered by intramuscular injection monthly and bimonthly respectively.

The drugs in this class are effective in about 65-70% of patients.

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