Nateglinide is an oral antihyperglycemic agent used for the treatment of non-insulin-dependent diabetes mellitus (NIDDM). It belongs to the meglitinide class of short-acting insulin secretagogues, which act by binding to β cells of the pancreas to stimulate insulin release. Nateglinide is an amino acid derivative that induces an early insulin response to meals decreasing postprandial blood glucose levels. It should only be taken with meals and meal-time doses should be skipped with any skipped meal. Approximately one month of therapy is required before a decrease in fasting blood glucose is seen. Meglitnides may have a neutral effect on weight or cause a slight increase in weight. The average weight gain caused by meglitinides appears to be lower than that caused by sulfonylureas and insulin and appears to occur only in those naïve to oral antidiabetic agents. Due to their mechanism of action, meglitinides may cause hypoglycemia although the risk is thought to be lower than that of sulfonylureas since their action is dependent on the presence of glucose. In addition to reducing postprandial and fasting blood glucose, meglitnides have been shown to decrease glycosylated hemoglobin (HbA1c) levels, which are reflective of the last 8-10 weeks of glucose control. Meglitinides appear to be more effective at lowering postprandial blood glucose than metformin, sulfonylureas and thiazolidinediones. Nateglinide is extensively metabolized in the liver and excreted in urine (83%) and feces (10%). The major metabolites possess less activity than the parent compound. One minor metabolite, the isoprene, has the same potency as its parent compound.

Glyburide, a second-generation sulfonylurea antidiabetic agent, lowers blood glucose acutely by stimulating the release of insulin from the pancreas, an effect dependent upon functioning beta cells in the pancreatic islets. With chronic administration in Type II diabetic patients, the blood glucose lowering effect persists despite a gradual decline in the insulin secretory response to the drug. Extrapancreatic effects may be involved in the mechanism of action of oral sulfonyl-urea hypoglycemic drugs. The combination of glibenclamide and metformin may have a synergistic effect, since both agents act to improve glucose tolerance by different but complementary mechanisms. In addition to its blood glucose lowering actions, glyburide produces a mild diuresis by enhancement of renal free water clearance. Glyburide is twice as potent as the related second-generation agent glipizide. Sulfonylureas such as glyburide bind to ATP-sensitive potassium channels on the pancreatic cell surface, reducing potassium conductance and causing depolarization of the membrane. Depolarization stimulates calcium ion influx through voltage-sensitive calcium channels, raising intracellular concentrations of calcium ions, which induces the secretion, or exocytosis, of insulin. Glyburide is indicated as an adjunct to diet to lower the blood glucose in patients with NIDDM whose hyperglycemia cannot be satisfactorily controlled by diet alone. Glyburide is available as a generic, is manufactured by many pharmaceutical companies and is sold in doses of 1.25, 2.5 and 5 mg under many brand names including Gliben-J, Daonil, Diabeta, Euglucon, Gilemal, Glidanil, Glybovin, Glynase, Maninil, Micronase and Semi-Daonil. It is also available in a fixed-dose combination drug with metformin that is sold under various trade names, e.g. Bagomet Plus, Benimet, Glibomet, Gluconorm, Glucored, Glucovance, Metglib and many others.

Diazoxide is a drug which was approved by FDA for the treatment of secondary hyperinsulinemia. The drug exerts its action by binding to SUR1 subunit of ATP-sensitive potassium channel that leads to the channel opening.

The novel compounds clamikalant (HMR 1883) or its sodium salt HMR 1098) have been shown to block selectively Kir6.2/SUR1-composed K(ATP) channels. Clamikalant is under development by Aventis Pharma (formerly Hoechst Marion Roussel) for the potential treatment of heart arrest and ventricular arrhythmias. Nevertheless, clamikalant and its sodium salt did not pass the clinical trials

Tifenazoxide is a thiadiazine derivative patented by Novo Nordisk A/S as the opener of the KATP-regulated potassium channels useful in the treatment of the endocrine system diseases. Tifenazoxide is a selective opener of the beta-cell type (SUR1 / Kir6.2) KATP channel that characterized as competitive inhibitors of glibenclamide binding to membranes of HEK293 cells expressing human SUR1/Kir6.2and as potent inhibitors of insulin release in isolated rat islets. In clinical trials, Tifenazoxide administration leads to a decrease in insulin concentrations 1 h post-dose. This was accompanied by an increase in glucose and growth hormone concentrations (NS), but not of glucagon. During the OGTT a dose-dependent reduction in the 2 h glucose value was observed.

Tolazamide is an oral blood glucose lowering drug of the sulfonylurea class. Tolazamide appears to lower the blood glucose acutely by stimulating the release of insulin from the pancreas, an effect dependent upon functioning beta cells in the pancreatic islets. The mechanism by which tolazamide lowers blood glucose during long-term administration has not been clearly established. With chronic administration in Type II diabetic patients, the blood glucose lowering effect persists despite a gradual decline in the insulin secretory response to the drug. Extrapancreatic effects may be involved in the mechanism of action of oral sulfonylurea hypoglycemic drugs. Some patients who are initially responsive to oral hypoglycemic drugs, including tolazamide, may become unresponsive or poorly responsive over time. Alternatively, tolazamide may be effective in some patients who have become unresponsive to one or more other sulfonylurea drugs. In addition to its blood glucose lowering actions, tolazamide produces a mild diuresis by enhancement of renal free water clearance. Sulfonylureas likely bind to ATP-sensitive potassium-channel receptors on the pancreatic cell surface, reducing potassium conductance and causing depolarization of the membrane. Depolarization stimulates calcium ion influx through voltage-sensitive calcium channels, raising intracellular concentrations of calcium ions, which induces the secretion, or exocytosis, of insulin. Tolazamide is used for use as an adjunct to diet to lower the blood glucose in patients with non-insulin dependent diabetes mellitus (Type II) whose hyperglycemia cannot be satisfactorily controlled by diet alone.

Acetohexamide (trade name Dymelor) is a first-generation sulfonylurea medication used to treat diabetes mellitus type 2, particularly in people whose diabetes cannot be controlled by diet alone. It lowers blood sugar by stimulating the pancreatic beta cells to secrete insulin and by helping the body use insulin efficiently. The pancreas must produce insulin for this medication to work. Acetohexamide binds to an ATP-dependent K+ channel on the cell membrane of pancreatic beta cells. This inhibits a tonic, hyperpolarizing out flux of potassium, which causes the electric potential over the membrane to become more positive. This depolarization opens voltage-gated Ca2+ channels. The rise in intracellular calcium leads to increased fusion of insulin granule with the cell membrane, and therefore increased secretion of (pro) insulin. Acetohexamide extensively metabolized in the liver to the active metabolite hydroxyhexamide, which exhibits greater hypoglycemic potency than acetohexamide. Hydroxyhexamide is believed to be responsible for prolonged hypoglycemic effects. Symptoms of an acetohexamide overdose include hunger, nausea, anxiety, cold sweats, weakness, drowsiness, unconsciousness, and coma. Acetohexamide has been discontinued in the US market.

Chlorpropamide (DIABINESE®), is a sulfonylurea hypoglycemic agent used in the treatment of non-insulin-dependent diabetes mellitus not responding to dietary modification. It appears to lower the blood glucose acutely by stimulating the release of insulin from the pancreas, an effect dependent upon functioning beta cells in the pancreatic islets. The mechanism by which chlorpropamide (DIABINESE®) lowers blood glucose during long-term administration has not been clearly established. Extra-pancreatic effects may play a part in the mechanism of action of oral sulfonylurea hypoglycemic drugs. While chlorpropamide is a sulfonamide derivative, it is devoid of antibacterial activity. Chlorpropamide (DIABINESE®) may also prove effective in controlling certain patients who have experienced primary or secondary failure to other sulfonylurea agent.

Tolbutamide is an oral antihyperglycemic agent used for the treatment of non-insulin-dependent diabetes mellitus (NIDDM). It is structurally similar to acetohexamide, chlorpropamide and tolazamide and belongs to the sulfonylurea class of insulin secretagogues, which act by stimulating β cells of the pancreas to release insulin. Sulfonylureas lower blood glucose in patients with NIDDM by directly stimulating the acute release of insulin from functioning beta cells of pancreatic islet tissue by an unknown process that involves a sulfonylurea receptor (receptor 1) on the beta cell. Sulfonylureas inhibit the ATP-potassium channels on the beta cell membrane and potassium efflux, which results in depolarization and calcium influx, calcium-calmodulin binding, kinase activation, and release of insulin-containing granules by exocytosis, an effect similar to that of glucose.

Nateglinide is an oral antihyperglycemic agent used for the treatment of non-insulin-dependent diabetes mellitus (NIDDM). It belongs to the meglitinide class of short-acting insulin secretagogues, which act by binding to β cells of the pancreas to stimulate insulin release. Nateglinide is an amino acid derivative that induces an early insulin response to meals decreasing postprandial blood glucose levels. It should only be taken with meals and meal-time doses should be skipped with any skipped meal. Approximately one month of therapy is required before a decrease in fasting blood glucose is seen. Meglitnides may have a neutral effect on weight or cause a slight increase in weight. The average weight gain caused by meglitinides appears to be lower than that caused by sulfonylureas and insulin and appears to occur only in those naïve to oral antidiabetic agents. Due to their mechanism of action, meglitinides may cause hypoglycemia although the risk is thought to be lower than that of sulfonylureas since their action is dependent on the presence of glucose. In addition to reducing postprandial and fasting blood glucose, meglitnides have been shown to decrease glycosylated hemoglobin (HbA1c) levels, which are reflective of the last 8-10 weeks of glucose control. Meglitinides appear to be more effective at lowering postprandial blood glucose than metformin, sulfonylureas and thiazolidinediones. Nateglinide is extensively metabolized in the liver and excreted in urine (83%) and feces (10%). The major metabolites possess less activity than the parent compound. One minor metabolite, the isoprene, has the same potency as its parent compound.