SITAGLIPTIN
Working
Sitagliptin inhibits an enzyme (called dipeptidyl protease IV, DPP IV) and so prolongs the
action of the hormone glucagon-like polypeptide 1 (GLP-1) that is released from the intestine in response to
food. The prolonged activity of the released GLP-1 lowers glucose levels by three different
means:
• It stimulates the release of insulin from beta
cells.
• It inhibits glucagon release from alpha cells.
• It slows down stomach emptying.
The usual dose is 100 mg once a day and is reduced to 50 mg or 25 mg if there is kidney
failure. In experimental animals, it seems to have a protective effect on beta cells. This has not yet been
shown in humans. It does not cause hypoglycemia when used on its own. Sitagliptin does not reduce appetite and
does not cause weight loss. Vildagliptin (Galvus), another DPP IV inhibitor, is likely to become available in
the future.
Side Effects
The main side effects of sitagliptin appear to be a sore throat
and headaches. There was also a small increase in the number of white blood cells (these are the cells that fight
bacterial infections). It has only recently been approved for clinical use, so long-term safety data is
lacking.
|