Pharmacological approach to the treatment of acromegaly

The treatment of patients with persistently active acromegaly has been facilitated over the past decade by the advent of highly specific and selective pharmacological agents. Somatostatin analogs, derived from the native inhibitory hormone somatostatin, are available in extended-duration preparations and are effective in reducing serum levels of growth hormone (GH) and insulin-like growth factor-I (IGF-I) as well as in improving the adverse clinical effects of acromegaly. Cabergoline, an agonist with a specificity for the dopamine D-2 receptor, has been shown to suppress IGF-I levels and induce tumor shrinkage in 35 and 50% of patients, respectively. The GH receptor antagonists compete with naturally occurring GH for binding with the GH receptor. As such, pegvisomant normalizes circulating IGF-I levels in 80 to 90% of patients with acromegaly. This last line of therapy should be considered for use in patients in whom surgery and medical therapy with somatostatin and/or dopamine agonists are either ineffective or poorly tolerated.