Polymyxin B is a lipopeptide antibiotic isolated from Bacillus polymyxa. Its basic structure consists of a polycationic peptide ring and a tripeptide side chain with a fatty acid tail. Polymyxin B is a mixture of at least four closely related components, polymyxin B1 to B4, with polymyxin B1 and B2 being the two major components. Polymyxin B acts on Gram-negative bacteria by interacting with lipopolysaccharide (LPS) of the outer membrane and destabilizing it. Polymyxin B is indicated for the treatment of many bacterial diseases such as meningeal infections, urinary tract infections and bacteremia.

Secretin is a peptide hormone produced by S-cells of the small intestinal mucosa and involved in the regulation of pancreatic secretory activity. S-cells that are located in the mucous membrane of the duodenum and in the proximal part of the jejunum secrete the polypeptide prosecretin, an inactive precursor of secretin, which turns into secretin by the action of hydrochloric acid of the gastric juice. Being absorbed into the blood, secretin reaches the pancreas and pancreatic centroacinar cells have secretin receptors in their plasma membrane. As secretin binds to these receptors, it enhances the secretion of bicarbonate-rich fluid that flows into the intestine. Bicarbonate is a base that neutralizes the acid, thus establishing a pH favorable to the action of other digestive enzymes in the small intestine. Secretin also increases water and bicarbonate secretion from duodenal Brunner's glands to buffer the incoming protons of the acidic chyme and also reduces acid secretion by parietal cells of the stomach. Secretin is used in a diagnostic test for pancreatic function.

Ergoloid mesylates (USAN), co-dergocrine mesilate (BAN) or dihydroergotoxine mesylate, trade name Hydergine, is a mixture of the methanesulfonate salts of three dihydrogenated ergot alkaloids (dihydroergocristine, dihydroergocornine, and alpha- and beta-dihydroergocryptine). It was developed by Albert Hofmann (the inventor of LSD) for Sandoz (now part of Novartis). Ergoloid mesylates act centrally, decreasing vascular tone and slowing the heart rate, and acts peripherally to block alpha-receptors. One other possible mechanism is the effect of ergoloid mesylates on neuronal cell metabolism, resulting in improved oxygen uptake and cerebral metabolism, thereby normalizing depressed neurotransmitter levels. Ergoloid Mesylate may increase cerebral metabolism and blood flow. The role of this medication in the therapy of dementia is controversial. A recent controlled study in patients with Alzheimer's disease found that there was no advantage to the use of ergoloid mesylates compared to placebo, suggesting that ergoloid mesylates may lower scores on some cognitive and behavioral rating scales. Further study is needed to determine the risk-benefit profile of ergoloid mesylates in the treatment of dementia.

Kanamycin (a mixture of kanamycin A, B and C) is an aminoglycoside bacteriocidal antibiotic, available in oral, intravenous, and intramuscular forms, and used to treat a wide variety of infections. It is effective against Gram-negative bacteria and certain Gram-positive bacteria. Aminoglycosides work by binding to the bacterial 30S ribosomal subunit, causing misreading of t-RNA, leaving the bacterium unable to synthesize proteins vital to its growth. Serious side effects include tinnitus or loss of hearing, toxicity to kidneys, and allergic reactions to the drug. Mixing of an aminoglycoside with beta-lactam-type antibiotics (penicillins or cephalosporins) may result in a significant mutual inactivation. Even when an aminoglycoside and a penicillin-type drug are administered separately by different routes, a reduction in aminoglycoside serum half-life or serum levels has been reported in patients with impaired renal function and in some patients with normal renal function.

Parathyroid hormone (PTH) is an 84-amino acid peptide that regulates the function of osteoblasts and osteocytes and is secreted by the parathyroid gland in response to changes in the concentration of extracellular calcium. Parathyroid hormone is approved under the brand name NATPARA as an adjunct to calcium and vitamin D to control hypocalcemia in patients with hypoparathyroidism. It is also available for treatment of postmenopausal osteoporosis in many European countries. Parathyroid hormone is an activator of parathyroid hormone 2 receptor. In addition, was shown, that downregulation of Notch in osteoblasts and osteocytes may represent a mechanism contributing to the anabolic effects of parathyroid hormone in bone.

Liraglutide is an acylated human Glucagon-Like Peptide-1 (GLP-1) receptor agonist with 97% amino acid sequence homology to endogenous human GLP-1(7-37). GLP-1(7-37) represents <20% of total circulating endogenous GLP-1. Like GLP-1(7-37), liraglutide activates the GLP-1 receptor, a membranebound cell-surface receptor coupled to adenylyl cyclase by the stimulatory G-protein, Gs, in pancreatic beta cells. Liraglutide increases intracellular cyclic AMP (cAMP) leading to insulin release in the presence of elevated glucose concentrations. This insulin secretion subsides as blood glucose concentrations decrease and approach euglycemia. Liraglutide also decreases glucagon secretion in a glucose-dependent manner. The mechanism of blood glucose lowering also involves a delay in gastric emptying. GLP-1(7-37) has a half-life of 1.5-2 minutes due to degradation by the ubiquitous endogenous enzymes, dipeptidyl peptidase IV (DPP-IV) and neutral endopeptidases (NEP). Unlike native GLP-1, liraglutide is stable against metabolic degradation by both peptidases and has a plasma half-life of 13 hours after subcutaneous administration. The pharmacokinetic profile of liraglutide, which makes it suitable for once daily administration, is a result of self-association that delays absorption, plasma protein binding and stability against metabolic degradation by DPP-IV and NEP. Liraglutide, a subcutaneous, once-daily GLP-1 agonist, is approved for the treatment of type 2 diabetes in the United States and Europe. It also has been studied for weight loss. Liraglutide helps to induce and sustain weight loss in patients with obesity. Its efficacy is comparable to other available agents but it offers the unique benefit of improved glycemic control.