ABSTRACT
Over-secretion of GH is usually associated with a functional adenoma of the acidophil cells of the adenohypophysis, and treatment is by neurosurgery and radiotherapy. The place of medical treatment is as an adjunct to this when surgery has not effected a cure, and while awaiting the effect of radiotherapy, which can be delayed by up to ten years. The visual fields and size of the pituitary fossa must be assessed repeatedly in order to detect further growth of the tumour during such treatment. Somatostatin lowers GH levels in acromegalics, but has to be given by continuous intravenous infusion and also inhibits many gastro-intestinal hormones. Octreotide and lanreotide are long-acting analogues of somatostatin which lower somatotropin levels. They are given by intermittent injection. Pegvisomant is a selective antagonist of the GH receptor. It is a genetically modified GH analogue and is injected subcutaneously once daily. It is used for acromegaly with an inadequate response to surgery, radiotherapy and somatostatin analogues. It has a range of gastro-intestinal, metabolic, neurological and other adverse effects and should be used only by physicians experienced in treating acromegaly.
