Continuing versus stopping sitagliptin when starting insulin glargine therapy in type 2 diabetes

This study aimed to compare the effects of continuing versus stopping sitagliptin (Januvia) when starting insulin glargine (Lantus) therapy in patients with type 2 diabetes. The main finding of the study was that those who continued sitagliptin after starting insulin glargine had better blood glucose control without an increase in side effects.

There are a number of drugs that can be used to lower blood glucose levels in patients with type 2 diabetes (T2D). Sitagliptin is a DPP-4 inhibitor. It works by making the body produce more insulin, the hormone that controls blood glucose. It is often used in combination with other glucose-lowering drugs for better blood glucose control. However, this does not work with every patient. If a combination of drugs is not working to sufficiently control blood glucose levels, insulin therapy is used as a last resort.

Insulin works very effectively, however, it can cause blood sugar levels to go dangerously low (hypoglycemia). When starting insulin therapy, patients are started on a low dose of insulin and then it is increased slowly until blood sugar is well controlled. Insulin glargine is a long-acting type of insulin. It is still not known whether continuing sitagliptin when starting insulin glargine is safe or if it could help control blood sugar levels more effectively.

This study included 743 patients with T2D. Patients were randomly assigned to either continue taking sitagliptin (373patients) after starting insulin glargine therapy or to stop taking sitagliptin after starting insulin glargine therapy (370 patients). The patients who stopped taking sitagliptin were given a placebo instead (a drug that has no effect on the body). Patients were treated for 30 weeks.

The group that continued sitagliptin had greater reductions in their HbA1c (blood test measuring long-term blood sugar control) compared to those who had stopped it. There were also 24% fewer episodes of hypoglycemia in the sitagliptin-taking group. The group that were continuing to take sitagliptin required lower doses of insulin glargine than those who were not taking sitagliptin.

The authors concluded that continuing sitagliptin, instead of stopping it, when starting insulin glargine leads to better blood glucose control, without an increase in hypoglycemia.

This study was funded my Merk & Co., a developer of sitagliptin.