Combination therapy in type 2 diabetes mellitus: adding linagliptin to a stable regimen of metformin and a sulfonylurea.

Linagliptin, the most recently approved drug of the dipeptidyl peptidase-4 (DPP-4) inhibitor class, is an oral agent used to improve glycemic control in type 2 diabetes mellitus (T2DM). By inhibiting the DPP-4 enzyme, these drugs slow the inactivation of the endogenous incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), in turn reducing blood glucose levels in a glucose-dependent manner. As well as significantly reducing glycosylated hemoglobin, the class has a good safety profile, with a low incidence of hypoglycemia, and is not associated with weight gain. From a practical point of view, they also have simple regimens, generally with once-daily oral administration, and can be used as monotherapy or in combination with other anti-diabetic drugs. Owens and colleagues have reported a 6-month study of linagliptin add-on therapy in patients who were receiving a stable regimen of metformin and a sulfonylurea, but needed additional glycemic control. Linagliptin was associated with significant improvement in glycemic control and was well-tolerated by patients, indicating that it provides a valuable option for a large number of patients with T2DM, especially for those who would prefer to add an oral therapy to a current regimen.