somatostatin analog

A somatostatin analog is a man-made version of somatostatin, the body's universal 'off' signal for hormone secretion. Natural somatostatin tells many glands — the pituitary, pancreas, and gut endocrine cells — to quiet down, but it disappears from the blood within minutes. These analogs are engineered to do the same job while lasting hours to weeks, making them practical drugs.

Their value is in switching off hormone-secreting tumors. By binding somatostatin receptors on the tumor cells, drugs such as octreotide and lanreotide suppress the runaway release of hormones and can also slow tumor growth. In acromegaly they lower excess growth hormone and IGF-1; in functioning neuroendocrine tumors they curb the flooding of substances that cause flushing, diarrhea, and other syndromes.

Because somatostatin's normal duties include slowing the gut and inhibiting insulin and digestive enzymes, the analogs share those effects as side effects: gallstones from sluggish bile flow, bloating and loose stools, and shifts in blood sugar. Most are given by injection, often as long-acting depot formulations administered every few weeks, and certain radioactively labeled versions can even be used to image or treat receptor-bearing tumors.