Long-acting formulations of somatostatin analogues.

Somatostatin has represented a significant breakthrough in the treatment of patients with hormonally-acting, neuroendocrine gastroenteropancreatic neoplasms, even if its short half-life made it impractical in the clinic. In recent years, new long-acting formulations have been developed from the native peptide. The long-lasting formulation of the somatostatin analogue octreotide (octreotide-LAR) can be administered once-monthly and has been shown to provide similar efficacy to subcutaneous octreotide administered three times a day in the control of flushing and diarrhoea associated with the carcinoid syndrome. Another-long acting somatostatin analogue, lanreotide, is available in a slow-release form, lanreotide-SR. In a multicentre 6-month trial on carcinoid tumour patients, 30 mg lanreotide-SR were administered intramuscularly every 14 days, obtaining the control of symptoms in the majority of subjects. Thus, both octreotide-LAR administered monthly, and lanreotide-SR administered every 10-14 days, have been shown to be an effective tool in the treatment of carcinoid tumours, providing, in addition, a substantial improvement in patient compliance.