Medical
therapy plays an important role in the management of
acromegaly.
Dopamine agonists and
somatostatin analogs are two classes of drugs approved for this purpose worldwide.
Pegvisomant, a
growth hormone receptor antagonist, has recently been evaluated in clinical trials.
Somatostatin analogs have been the mainstay of medical treatment during the last 10 yr with their acceptability enhanced by the development of
depot preparations.
Somatostatin analogs improve symptoms and signs of
acromegaly in the majority, normalize IGF- 1 in up to 60%, and result in
tumor shrinkage in up to half of patients.
Dopamine agonists have modest efficacy and limited tolerability. They are more effective in mixed GH/
prolactin-secreting
tumors. Newer agonists with D2 receptor specificity have fewer side effects but are less efficacious than
somatostatin analogs. The addition of a
dopamine agonist to
somatostatin analog
therapy can result in greater biochemical control than with individual agents.
Pegvisomant is the most effective
drug treatment for
acromegaly, but it is likely to have a major adjuvant role as its mechanism of action is not directed at the
tumor. The availability of more effective and better tolerated
drug therapies offers greater flexibility and individualization of
therapy that will lead to improved patient care and disease control.