Drug therapy for portal hypertension
Michael JG Farthing, Anne B Ballinger in Drug Therapy for Gastrointestinal and Liver Diseases, 2019
Octreotide is a synthetic long-acting somatostatin analogue that has been shown to be significantly more efficient than the native hormone in treating acromegaly and endocrine tumours.62 This greater efficacy arises from the fact that octreotide is significantly more potent than natural somatostatin in inhibiting growth hormone and glucagon release.62 This advantage, in addition to its long half-life and easy administration (octreotide can be administered subcutaneously), have led to the clinical use of octreotide in conditions other than those previously mentioned and in which somatostatin has clearly shown to be highly efficient, such as portal hypertension and its related complications. Although octreotide has been shown to reduce portal pressure in animals,63 however, this effect is uncertain in cirrhotic patients.63, 64
Non-Surgical Management of Thyroid Cancer
John C Watkinson, Raymond W Clarke, Louise Jayne Clark, Adam J Donne, R James A England, Hisham M Mehanna, Gerald William McGarry, Sean Carrie in Basic Sciences Endocrine Surgery Rhinology, 2018
If a patient responds favourably to a twice or three times daily subcutaneous administration of octreotide, a synthetic somatostatin analogue, with a reduction in diarrhoea frequency or severity, then they can be commenced on a monthly depot preparation. With prolonged use, there is a risk of tachyphylaxis developing with loss of symptomatic benefit. However, if symptom control deteriorates, it is important to consider if disease progression is the cause before attributing the change to tachyphylaxis. Octreotide and lanreotide have a different spectrum of somatostatin receptor blockade. Side effects of the somatostatin analogues include gastrointestinal disturbances, such as anorexia, nausea, vomiting, abdominal pain, flatulence, diarrhoea and steatorrhoea, and rarely with long-term use gallstones may occur. Abnormalities of glucose metabolism may also occur. Local reactions at the site of administration may be seen and rotation of the injection site is recommended.
Peptide Receptor Therapy with 90Y-Dotatoc: The Emerging Experience in Chile
Marco Chinol, Giovanni Paganelli in Radionuclide Peptide Cancer Therapy, 2016
Most neuroendocrine tumors (NT) and a few others, such as small cell lung cancer, hepatomas, lymphomas, breast cancer, and meningiomas, have a variable degree of over-expression of somatostatin receptors (SSTRs) on their cellular surface (1–4). Somatostatin is a tetradecapeptide produced by the hypothalamus and pancreas with a very short biological half-life. It is possible to recognize five different sub-types (5) of SSTRs, with the SSTR2 sub-type as the most prevalent. The synthetic variant of the human somatostatin with a chain of 8 peptides, named Octreotide, has the advantage of a prolonged “in vivo” half-life retaining its specificity for the cellular receptors. These characteristics allow the detection of both primary tumors and their metastases by diagnostic scintigraphic images with this polypeptide labeled with In (6–7).
Octreotide and Octreotide-derived delivery systems
Published in Journal of Drug Targeting, 2023
Mingliang Fan, Yue Huang, Xinlin Zhu, Jiayu Zheng, Mingwei Du
The tetradecapeptide somatostatin is secreted by hypothalamus or delta cells in gastrointestinal tract and interacts with somatostatin receptors (SSTRs), which is a group of GPCRs (G-protein-coupled receptors) with five human receptor subtypes (SSTR 1-5). Somatostatin can inhibit the release of a series of hormones or neuropeptides in many organs, including growth hormone, insulin, glucagon, among others, thus taking important roles in many physiological functions. However, its clinical applications are remarkably restricted by poor circulation time (about 3 min) in the blood. Hence a variety of somatostatin analogs with longer circulation time have been developed for clinical use since 1970s [1]. Among them, Octreotide (SMS 201-995) is the most widely developed representative of somatostatin analog and stands the test of clinical application [2]. As a therapeutic agent and targeting ligand, Octreotide (OCT) has also been involved in the construction of many novel pharmaceutical systems for tumour targeted treatment. Given OCT-derived radionuclide therapy and radionuclide imaging were well reviewed by previous publication [3], we herein focus on the preclinical studies of some novel pharmaceutical delivery systems related to OCT, including microsphere, conjugate, liposome, polymeric nanoparticle, hydrogel and inorganic nanoparticle.
Current advances in the management of cluster headaches
Published in Expert Opinion on Pharmacotherapy, 2021
Theodoros Mavridis, Marianthi Breza, Christina Deligianni, Dimos D. Mitsikostas
Octreotide is a somatostatin analog that mimics natural somatostatin by inhibiting serotonin release, and the secretion of gastrin, VIP, insulin, glucagon, secretin, motilin, and pancreatic polypeptide. It provides more potent inhibition of growth hormone, glucagon, and insulin as compared to endogenous somatostatin. Octreotide has a level C recommendation for the acute treatment of CH [29]. Octreotide 100 mg given subcutaneously has shown effectiveness in improving headache response compared to placebo. In terms of response rate and time to initial relief, it is believed to be inferior to both subcutaneous and intranasal sumatriptan [42,43]. The adverse effects (AE) are nonserious and include injection site reactions, diarrhea, abdominal bloating, nausea, dull background headache and dizziness/somnolence [27,29].
The effect of infliximab and octreotide on cytokine levels experimental proliferative vitreoretinopathy
Published in Cutaneous and Ocular Toxicology, 2020
Fatma Savur, Orhan Aydemir, Nevin İlhan
Octreotide is a long-acting synthetic octapeptide derivative of somatostatin. Somatostatin activates the tyrosine phosphatase enzyme, which in turn inactivates several growth factors, thus inhibiting their effects. Several in-vitro studies have shown that, due to its anti-proliferative actions, octreotide might inhibit the proliferation of retinal endothelial cells as well as retinal pigment epithelium (RPE), which constitutes the main components of the PVR membranes and plays essential roles in the development of the disease. This agent also inhibits several growth factors that take part in PVR etiopathogenesis45–47. Octreotide, which has been reported to have antioxidant, anti-proliferative, anti-oedema, anti-adhesive, and free radical scavenging effects in numerous studies, was also demonstrated to inhibit TGF-β1, a mediator of fibrosis development48. Somatostatin is also known to possess some anti-inflammatory properties49,50.
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