What is/are Sitagliptin?
Sitagliptin (INN; previously identified as MK-0431 and marketed as the phosphate salt under the trade name Januvia) is an oral antihyperglycemic (antidiabetic drug) of the dipeptidyl peptidase-4 (DPP-4) inhibitor class. It was developed, and is marketed, by Merck & Co. This enzyme-inhibiting drug is used either alone or in combination with other oral antihyperglycemic agents (such as metformin or a thiazolidinedione) for treatment of diabetes mellitus type 2. The benefit of this medicine is its fewer side effects (e.g., less hypoglycemia, less weight gain) in the control of blood glucose values. While safety is its advantage, efficacy is often challenged as it is often recommended to be combined with other agents like metformin.
In clinical trials, adverse effects were as common with sitagliptin (whether used alone or with metformin or pioglitazone) as they were with placebo, except for extremely rare nausea and common cold-like symptoms, including photosensitivity. There is no significant difference in the occurrence of hypoglycemia between placebo and sitagliptin.
There have been several postmarketing reports of pancreatitis (some fatal) in people treated with sitagliptin,and the U.S. package insert carries a warning to this effect, although the causal link between sitagliptin and pancreatitis has not yet been fully substantiated.
Mechanism of action
Sitagliptin works to competitively inhibit the enzyme dipeptidyl peptidase 4 (DPP-4). This enzyme breaks down the incretins GLP-1 and GIP, gastrointestinal hormones released in response to a meal. By preventing GLP-1 and GIP inactivation, they are able to increase the secretion of insulin and suppress the release of glucagon by the pancreas. This drives blood glucose levels towards normal. As the blood glucose level approaches normal, the amounts of insulin released and glucagon suppressed diminishes, thus tending to prevent an "overshoot" and subsequent low blood sugar (hypoglycemia) which is seen with some other oral hypoglycemic agents.
Sitagliptin has been shown to lower HbA1c level by about 0.7% points versus placebo. It is slightly less effective than metformin when used as a monotherapy and does not cause a weight gain compared to sulfonylureas. Sitagliptin is recommended as a second line drug (in combination with other drugs) after the treatment based on a combination of diet and metformin fails.
This article uses material from the Wikipedia article Sitagliptin, which is released under the Creative Commons Attribution-Share-Alike License 3.0.