A Somatostatin-Like Octapeptide, Octreotide Mimics Natural Somatostatin Pharmacologically

 

Octreotide

Octreotide is an octapeptide that pharmacologically mimics natural somatostatin. However, it is a more effective inhibitor of growth hormone, glucagon, and insulin than the natural hormone. It is marketed under the brand names Sandostatin and other names. It was first created in 1979 by the chemist Wilfried Bauer and primarily binds to the SSTR2 and SSTR5 somatostatin receptors. In the United States, it was given the go-ahead in 1988. In the European Union, octreotide (Mycapssa) was authorised for medicinal use in 2022. The FDA has only approved octreotide (Mycapssa), the first and only oral somatostatin analogue (SSA), as of June 2020.

Headache, hypothyroidism, cardiac conduction changes, gastrointestinal reactions (including cramps, nausea/vomiting, diarrhoea or constipation), gallstones, decreased insulin release, hyperglycemia or occasionally hypoglycemia, and (usually temporary) injection site reactions are the most frequent negative side effects. Slow heartbeat, pruritis and other skin responses, hyperbilirubinemia, hypothyroidism, dizziness, and dyspnea are also fairly frequent (greater than 1%). Acute allergic reactions, pancreatitis, and hepatitis are all uncommon adverse effects. According to certain research, patients who received Octreotide reported having alopecia. In a 1998 study, octreotide treatment resulted in erectile dysfunction in rats. Although a longer QT interval has been seen, it is unclear if this is a side effect of the medication or the result of an underlying medical condition.

The intestinal reabsorption of ciclosporin can be decreased by Octreotide, necessitating a possible dose increase. When treated with octreotide, people with diabetes mellitus may require less insulin or oral antidiabetics because it inhibits glucagon secretion more potently and for a longer period of time than insulin. Bromocriptine has a higher bioavailability; in addition to acting as an antiparkinsonian, it is also used to treat acromegaly.

People with acromegaly (condition in which the body produces too much growth hormone, causing enlargement of the hands, feet, and facial features; joint pain; and other symptoms) who cannot be treated with surgery, radiation, or another medication can use octreotide immediate-release injection to reduce the amount of growth hormone (a natural substance) produced. Additionally, carcinoid tumours (slow-growing tumours that generate natural compounds that might induce symptoms) and vasoactive intestinal peptide-secreting adenomas are treated with octreotide immediate-release injection to reduce diarrhoea and flushing (VIP-omas; tumours that form in the pancreas and release natural substances that can cause symptoms).