Dipeptidyl peptidase 4 inhibitors 

Dipeptidyl peptidase 4 (DPP-4) inhibitors are a class of medicine that lower high blood glucose levels and may be used in the treatment of type 2 diabetes.

DPP-4 inhibitors slow the inactivation and degradation of GLP-1, a hormone involved in glucose removal from the gut. DPP-4 inhibitors improve blood glucose control and reduce both fasting and postprandial (after food) blood glucose levels, without causing weight gain. They do not usually cause hypoglycemia (low blood sugar levels) unless they are combined with other therapies that cause hypoglycemia.

Saxagliptin is an incredibly selective and reversible DPP-4 inhibitor (Tahrani et al., 2009a). It can increase the GLP-1 levels to 1.5 to 3-fold with a single dose of 2.5–400 mg which inhibits DPP-4 activity between 50% and 79% (Chacra, 2010). Saxagliptin is tenfold more effective than vildagliptin and sitagliptin.