Medications

One goal of drug therapy in acromegaly is to normalize levels of growth hormone and IGF-1 in the bloodstream. Another is to shrink the tumor. 

Growth hormone receptor blockers are the newest category of drugs used for acromegaly. These drugs work by blocking the site on the cell where growth hormone "docks." If the growth hormone can't dock, it can't cause abnormal growth.

• The only drug in this category that has been approved by the US Food and Drug Administration (FDA) for acromegaly is pegvisomant (Somavert).
  
  
• In early studies, this drug normalized IGF-1 level in more than 90% of people treated.
  
• Pegvisomant is given by shots.
  
  
• Side effects include reaction at the injection site, sweating, headache, and fatigue. 

Somatostatin analogues act like the hormone somatostatin. They work by stopping secretion of growth hormone, just as somatostatin does.

• The most widely used drug in this group by far is octreotide (Sandostatin). This drug works in most people who take it.
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• Octreotide can be taken only as shots once monthly.
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• It causes gastrointestinal side effects such as nausea, bloating, and gas in about 30% of people who take it.

Dopamine agonists promote the activity of dopamine, a chemical in the brain. These drugs work by stopping secretion of growth hormone by some pituitary tumors.

• The most widely used of these drugs is bromocriptine (Parlodel). It is popular because it comes in a convenient oral form and is much less expensive than octreotide.
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• These drugs work in fewer than half of people who take them.
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• Side effects of these drugs include gastrointestinal upsets, lightheadedness when standing up, and sinus congestion.