Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011860 (type 2 diabetes)
 57,723 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Exenatide is a long-acting glucagon-like peptide-1 (GLP-1) mimetic used in the treatment of type 2 diabetes. There is increasing evidence that GLP-1 can influence glycemia not only via pancreatic (insulinotropic and glucagon suppression) and gastric-emptying effects, but also via an independent mechanism mediated by portal vein receptors. The aim of our study was to investigate whether exenatide has an islet- and gastric-independent glycemia-reducing effect, similar to GLP-1. First, we administered mixed meals, with or without exenatide (20 microg sc) to dogs. Second, to determine whether exenatide-induced reduction in glycemia is independent of slower gastric emptying, in the same animals we infused glucose intraportally (to simulate meal test glucose appearance) with exenatide, exenatide + the intraportal GLP-1 receptor antagonist exendin-(9-39), or saline. Exenatide markedly decreased postprandial glucose: net 0- to 135-min area under the curve = +526 +/- 315 and -536 +/- 197 mg.dl(-1).min(-1) with saline and exenatide, respectively (P < 0.05). Importantly, the decrease in plasma glucose occurred without a corresponding increase in postprandial insulin but was accompanied by delayed gastric emptying and lower glucagon. Significantly lower glycemia was induced by intraportal glucose infusion with exenatide than with saline (92 +/- 1 vs. 97 +/- 1 mg/dl, P < 0.001) in the absence of hyperinsulinemia or glucagon suppression. The exenatide-induced lower glycemia was partly reversed by intraportal exendin-(9-39): 95 +/- 3 and 92 +/- 3 mg/dl with exenatide + antagonist and exenatide, respectively (P < 0.01). Our results suggest that, similar to GLP-1, exenatide lowers glycemia via a novel mechanism independent of islet hormones and slowing of gastric emptying. We hypothesize that receptors in the portal vein, via a neural mechanism, increase glucose clearance independent of islet hormones.
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PMID:Exenatide can reduce glucose independent of islet hormones or gastric emptying. 1849 81

Incretin hormones, secreted upon food intake, play an important role in the regulation of blood glucose levels. In type 2 diabetes mellitus, the incretin response is decreased. Substitution of incretin is a novel pharmacological target which restores postprandial glucose homeostasis. Exenatide is a mimetic of the incretin glucagon-like peptide-I (GLP-I). Sitagliptin is an inhibitor of the enzyme dipeptidyl peptidase 4 (DPP-4), which breaks down GLP-I. Both drugs increase the GLP-I concentration, thereby improving insulin secretion from pancreatic p cells, restoring glycaemic control, preventing beta cell destruction, delaying gastric emptying, and reducing food intake.
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PMID:[New drugs; exenatide and sitagliptin]. 1871 16

There has been a dramatic increase in the prevalence of the most common form of diabetes, with approximately 14.6 million diagnosed and 6.2 million undiagnosed cases of type 2 (non-insulin-dependent) diabetes in the United States since 2005. If diabetes is not diagnosed early and managed properly, patients are at greater risk for microvascular and macrovascular complications, such as nerve damage, heart disease, blindness, and kidney damage. The pathogenesis of type 2 diabetes includes impaired insulin secretion, increased hepatic and muscle/fat insulin resistance, and increased glucagon secretion. Problems commonly associated with type 2 diabetes and consequent hyperglycemia are weight gain, hypertension, and dyslipidemia. The natural progression of type 2 diabetes involves increased insulin deficiency as a result of decreased beta cell function over time, which can raise glycosylated hemoglobin to dangerous levels and consequently increase the risk of death. Lifestyle modifications (eg, diet changes and increased physical activity) remain the cornerstone of early treatment, but glycemic control may worsen despite behavior changes and treatment with oral hypoglycemic agents. Historically, upon failure to maintain glucose levels with exercise and oral medication, insulin was the second-line treatment option. Current treatment algorithms include a new class of agents, incretin mimetics, such as the glucagon-like peptide-1 (GLP-1) receptor agonist exenatide. Exenatide mimics the actions of the hormone GLP-1 that occurs naturally in the gastrointestinal tract and has emerged as an efficacious therapy adjunct to 1 or more oral hypoglycemic agent(s).
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PMID:Exploring the pharmacotherapeutic options for treating type 2 diabetes. 1852 66

The improved understanding of glucoregulatory hormones has driven the development of new pharmacologic agents to treat type 2 diabetes. One new class of antihyperglycemic medication is incretin mimetics (IMs). Incretin hormones potentiate insulin secretion following meal ingestion, a process that is impaired in patients with type 2 diabetes. GLP-1, a 30-amino acid peptide incretin hormone, is produced in the L cells of the ileum and colon. Studies have shown that a 6-week continuous GLP-1 infusion in patients with type 2 diabetes improved glycemic control and beta-cell function and delayed gastric emptying. Despite the rapid degradation and inactivation of GLP-1 by the enzyme dipeptidyl peptidase IV (DPP-IV), agents that mimic the actions of GLP-1 are of great clinical interest. First-in-class IM exenatide, a GLP-1 receptor agonist resistant to DPP-IV inactivation, mimics many beneficial glucoregulatory effects of GLP-1, such as suppressing glucagon secretion, regulating gastric emptying and satiety, and increasing glucose-dependent insulin secretion. Exenatide is an adjunctive therapy for patients who take metformin, a sulfonylurea, a thiazolidinedione, or a combination of these oral medications but have not achieved glycemic control. An 82-week, open-label extension trial has shown that exenatide is well tolerated and that the benefits, including improved glycemic control, weight loss, and mitigation of cardiovascular risk factors, are sustained.
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PMID:Beyond glycemic control: the effects of incretin hormones in type 2 diabetes. 1852 67

Exenatide (Byetta) is a synthetic derivative of exendin-4 and an agonist of receptors of glucagon-like peptide-1 (GLP-1). It is resistant to the rapid inactivation by dipeptidylpeptidase-4 and acts as an incretin mimetic. It stimulates insulin secretion by the B cell in a glucose-dependent manner whereas it inhibits glucagon secretion. Exenatide improves mainly postprandial glucose concentrations and lowers glycated haemoglobin (HbA(1c)) levels, without being directly responsible for hypoglycaemia or requiring mandatory home blood glucose monitoring. Furthermore, it slows down gastric emptying and promotes sustained body weight reduction, even in absence of frequently reported nausea following treatment initiation. Exenatide is recommended and reimbursed in Belgium for the treatment of type 2 diabetes, in combination with metformin and a sulfonylurea, in patients not adequately controlled with maximal tolerated doses of these oral glucose-lowering agents. Exenatide is presented as pre-filled pens for subcutaneous injection. The recommended initial dose is 5 microg before morning and evening meals, to be up titrated to 10 microg twice daily. Exenatide may represent a valuable alternative to insulin therapy, especially in overweight or obese patients with type 2 diabetes and not ready to perform home blood glucose monitoring.
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PMID:[Medication of the month... Exenatide (Byetta) incretinomimetic in the treatment of type 2 diabetes after failure and as add-on therapy to oral agents]. 1856 73

For many patients with type 2 diabetes mellitus, metformin plus appropriate treatment for cardiovascular risk factors form the cornerstone of drug therapy.1 However, the progressive impairment of both the secretion and action of insulin in the condition mean that high blood glucose concentrations usually worsen over time, so necessitating escalation of hypoglycaemic therapy. Three drugs in two new classes that act on the hormonal regulation of insulin secretion have been launched recently for use as add-in therapies in patients with type 2 diabetes: exenatide (Byetta--Eli Lilly), sitagliptin (Januvia--MSD), and vildagliptin (Galvus--Novartis). Here we consider whether they have a role in the management of such individuals.
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PMID:Three new drugs for type 2 diabetes. 1860 39

The demonstration that the incretin hormone glucagon-like peptide 1 can improve glycaemic control in patients with type 2 diabetes has led to the rapid development during the last decade of promising new classes of agent for the management of type 2 diabetes. These agents possess a range of physiological effects that are associated with improved glycaemic control in diabetes including stimulation of glucose-dependent insulin secretion, suppression of glucagon secretion, slowing of gastric emptying, and reduction of food intake. In addition, preclinical studies suggest that incretin-based therapies may improve beta-cell function via enhancement of beta-cell mass and induction of genes important for differentiated beta-cell function. Exenatide, and the dipeptidyl peptidase-4 inhibitors, sitagliptin and vildagliptin are already approved, and liraglutide is currently completing Phase 3 trials. As these agents and standard oral therapies for type 2 diabetes lower glucose levels through different, but potentially complementary mechanisms, their use in combination should provide effective, potentially additive, glycaemic control. The incretin-based therapies also offer other advantages such as weight loss with exenatide and liraglutide, a reduced risk of hypoglycaemia, and as suggested by preclinical studies, a potential beta-cell preserving effect. Long-term outcome and safety data are not available for these agents, but they appear generally well-tolerated in comparison with existing therapies for type 2 diabetes. The multiple underlying glucose-lowering actions of the incretin-based therapies, as well as a lack of weight gain or even weight loss, make these important new additions to available antidiabetic agents expanding the treatment options available for patients.
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PMID:New treatments in type 2 diabetes: a focus on the incretin-based therapies. 1877 70

The incretin hormones are released during meals from gut endocrine cells. They potentiate glucose-induced insulin secretion and may be responsible for up to 70% of postprandial insulin secretion. The incretin hormones include glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), both of which may also promote proliferation/neogenesis of beta cells and prevent their decay (apoptosis). Both hormones contribute to insulin secretion from the beginning of a meal and their effects are progressively amplified as plasma glucose concentrations rise. The current interest in the incretin hormones is due to the fact that the incretin effect is severely reduced or absent in patients with type 2 diabetes mellitus (T2DM). In addition, there is hyperglucagonaemia, which is not suppressible by glucose. In such patients, the secretion of GIP is near normal, but its effect on insulin secretion, particularly the late phase, is severely impaired. The loss of GIP action is probably a consequence of diabetes, since it is also observed in patients with diabetes secondary to chronic pancreatitis, in whom the incretin effect is also lost. GLP-1 secretion, on the other hand, is also impaired, but its insulinotropic and glucagon-suppressive actions are preserved, although the potency of GLP-1 in this respect is decreased compared to healthy subjects. However, in supraphysiological doses, GLP-1 administration may completely normalize beta as well as alpha cell sensitivity to glucose. The impaired action of GLP-1 and GIP in T2DM may be at least partly restored by improved glycaemic control, as shown in studies involving 4 weeks of intensive insulin therapy. The reduced incretin effect is believed to contribute to impaired regulation of insulin and glucagon secretion in T2DM, and, in support of this, exogenous GLP-1 administration may restore blood glucose regulation to near normal levels. Thus, the pathogenesis of T2DM seems to involve a dysfunction of both incretins. Enhancement of incretin action may therefore represent a therapeutic solution. Clinical strategies therefore include the development of metabolically stable activators of the GLP-1 receptor; and inhibition of DPP-4, the enzyme that destroys native GLP-1 almost immediately. Orally active DPP-4 inhibitors and the metabolically stable activators, exenatide (Byetta), are now on the market, and numerous clinical studies have shown that both principles are associated with durable antidiabetic activity.
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PMID:The incretin system and its role in type 2 diabetes mellitus. 1878 5

The benefits and drawbacks of exenatide as an alternative to insulin in the treatment of poorly regulated type 2 diabetes are reviewed. Exenatide and insulin have equal effects on HbA1c but exenatide causes weight-loss and improved postprandial glucose control. Nausea is reported by nearly half of patients treated with exenatide. Exenatide can be considered in the overweight patient without extremely elevated HbA1c but nausea could pose a substantial hurdle for successful treatment.
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PMID:[Exenatide--an alternative to insulin in the treatment of type 2 diabetes?]. 1882 27

In this single-blind, parallel, placebo-controlled study, the pharmacokinetics, pharmacodynamics, tolerability, and safety of subcutaneous exenatide were evaluated in 40 Japanese patients with type 2 diabetes. Patients were allocated to 4 groups and randomized to receive exenatide (n = 8/group) or placebo (n = 2/group), with all receiving placebo on day 1. On day 2, patients received single-dose exenatide (2.5 microg [group A] or 5 microg [groups B, C, and D]) or placebo and then bid on days 3 to 5. On days 6 to 10, groups A and B continued on 2.5 and 5 microg bid; groups C and D received 10 and 15 microg bid, respectively. The last dose was given on the morning of day 10. All adverse events were mild or moderate in severity. Exenatide was generally well tolerated up to 10 microg. Exenatide was well absorbed with a median t(max) of 1.5 hours and mean t((1/2)) of 1.6 hours; exposure increased with dose. Up to 10 microg, exenatide reduced postprandial glucose concentrations in a dose-dependent fashion compared with placebo; decreases were similar for 10 and 15 microg. An E(max) model demonstrated that doses higher than 2.5 microg were necessary for adequate glycemic response. Based on tolerability and pharmacokinetic/pharmacodynamic relationships, 5 and 10 microg exenatide may be considered for further clinical development in Japanese patients with type 2 diabetes.
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PMID:Pharmacokinetics, pharmacodynamics, tolerability, and safety of exenatide in Japanese patients with type 2 diabetes mellitus. 1904 64


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