BIOLOGICAL SIGNIFICANCE

Octreotide is the acetate salt of a cyclic octapeptide. It is a long-acting octapeptide with pharmacologic properties mimicking those of the natural hormone somatostatin. Octreotide is known chemically as L-Cysteinamide, D – phenylalanyl – L – cysteinyl - L-phenylalanyl - D – tryptophyl – L – lysyl – L – threonyl – N - [2 – hydroxy – 1 -(hydroxy-methyl) propyl] -, cyclic (2®7)- disulfide; [R-(R*,R*)].

Octreotide is a somatostatic agent. It works by reducing blood levels of a variety of hormones (eg, growth hormone) and chemical messengers (eg, gastrin, vasoactive intestinal peptide), which cause disease symptoms.

CLINICAL USE

Treatment of severe diarrhea caused by certain types of cancer.

It is also used to treat acromegaly in certain patients.

Octreotide is also used to reduce flushing episodes and watery diarrhea caused by cancerous tumors (carcinoid syndrome) or tumors called vasoactive intestinal peptide tumors (VIP adenomas).

Octreotide is used for the control of symptoms associated with functional neuroendocrine tumors.

MODE OF ACTION

The acetate salt of a synthetic long-acting cyclic octapeptide with pharmacologic properties mimicking those of the natural hormone somatostatin. Octreotide is a more potent inhibitor of growth hormone, glucagon, and insulin than somatostatin. Similar to somatostatin, this agent also suppresses the luteinizing hormone response to gonadotropin - releasing hormone, decreases splanchnic blood flow, and inhibits the release of serotonin, gastrin, vasoactive intestinal peptide (VIP), secretin, motilin, pancreatic polypeptide, and thyroid stimulating hormone.

STRUCTURE: