Somatostatin and Its Analogues as Second-Line Treatments in Non-Neoplastic Conditions

Somatostatin is a potent endocrine regulator and neurotransmitter, exerting predominantly inhibitory effects in different tissues of the body, via G-protein coupled receptors. Five such specific receptors have been identified, with different effects and tissue distribution. The multifaceted actions and effects of somatostatin make it useful as a potential therapeutical means in various pathologies; however, in clinical practice, somatostatin analogues, namely octreotide, lanreotide and pasireotide, are commonly used instead, due to their increased half-life and increased receptor selectivity, with pasireotide showing a more extensive receptor binding profile and high affinity for somatotastin receptor (SSTR) 5, which may prove effective in cases of resistance to first-generation analogues. Apart from their many uses in neoplastic pathologies, somatostatin analogues represent viable treatment choices in some ocular pathologies, congenital hyperinsulinism, gastrointestinal bleedings and portal hypertension, acute pancreatitis, and dumping syndrome. They have also been used in some cases, with varying degrees of success, in patients with post-surgical gastrointestinal and lymphatic fistulas, refractory chronic diarrhoea and polycystic kidney disease; many applications in paediatric patients have also been documented. The aim of this review is to present the applications of somatostatin and its analogues as alternative or second-line therapies, along with insights into their effectiveness and future potential.