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KEY CONCEPTS
Pharmacologic therapy for acromegaly should be considered when surgery and irradiation are contraindicated, when there is poor likelihood of surgical success, when rapid control of symptoms is needed, or when other treatments have failed to normalize growth hormone (GH) and insulin-like growth factor-1 (IGF-1) serum concentrations.
Pharmacotherapy for acromegaly using dopamine agonists provides advantages of oral dosing and reduced cost compared to somatostatin analogs and pegvisomant. However, dopamine agonists effectively normalize IGF-1 serum concentrations in only 10% of patients. Therefore, somatostatin analogs remain the mainstay of therapy.
Blood glucose concentrations should be monitored frequently in the early stages of somatostatin analog therapy for acromegaly.
Pegvisomant appears to be the most effective agent for normalizing IGF-1 serum concentrations. However, further study is needed to determine the long-term safety and efficacy of this agent for the treatment of acromegaly.
Recombinant GH is currently considered the mainstay for treatment of children with growth hormone-deficient short stature. Prompt diagnosis of growth hormone deficiency (GHD) and initiation of replacement therapy with recombinant GH is crucial for optimizing final adult heights.
All GH products are generally considered to be equally effective. The recommended dose for treatment of GHD short stature in children is 0.3 mg/kg/wk.
Pharmacologic agents that antagonize dopamine or increase the release of prolactin can induce hyperprolactinemia. Discontinuation of the offending medication and initiation of an appropriate therapeutic alternative usually normalizes serum prolactin concentrations.
Cabergoline appears to be more effective than bromocriptine for the medical management of prolactinomas and offers the advantage of less-frequent dosing and fewer adverse effects.
Although preliminary data do not suggest cabergoline has significant teratogenic potential, cabergoline is not recommended for use during pregnancy, and patients receiving cabergoline who plan to become pregnant should discontinue the medication as soon as pregnancy is detected.
Pharmacologic treatment of panhypopituitarism includes the use of glucocorticoids, thyroid hormone, sex steroids, and recombinant GH, where appropriate, as lifelong replacement therapies.
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In the 1950s, Geoffrey Harris and his colleagues uncovered the physiologic importance of pituitary hormones and proposed the theory of neurohormonal regulation of the pituitary by the hypothalamus.1 Today the pituitary gland is recognized for its essential role in body homeostasis, and for this reason it is often referred to as the master gland. The hypothalamus and the pituitary gland are closely connected, and together they provide a means of communication between the brain and many of the body’s endocrine organs. The hypothalamus uses nervous input and metabolic signals from the body to control the secretion of pituitary hormones that regulate growth, thyroid function, adrenal activity, reproduction, lactation, and fluid balance.
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ANATOMY AND PHYSIOLOGY
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The hypothalamus (Fig. e77-1) is a small region at the base of the brain that receives autonomic nervous input from different areas of the body to regulate limbic functions, food and water intake, body temperature, cardiovascular function, respiratory function, and diurnal rhythms. In addition, the ...