Continuing DPP-4 Inhibitors with Insulin Therapy

Introduction to Combination Therapy

The American Diabetes Association recommends continuing metformin and other beneficial oral hypoglycemic agents, including DPP-4 inhibitors like sitagliptin, when starting insulin therapy, as this approach leverages complementary mechanisms of action to optimize glycemic control while minimizing adverse effects 1
The American Diabetes Association explicitly recommends continuing metformin and other beneficial oral hypoglycemic agents, including DPP-4 inhibitors like sitagliptin, when starting insulin therapy, as part of their treatment regimen, which is safe, effective, and recommended by current guidelines 1

Metformin should always be continued unless contraindicated, due to complementary action and cardiovascular benefits, as recommended by the American Diabetes Association 1, 2
SGLT2 inhibitors may be continued for cardiorenal benefits, especially in patients with heart failure or chronic kidney disease, as recommended by the American Heart Association 1, 2
Sulfonylureas should be reduced or discontinued due to increased hypoglycemia risk when combined with insulin, as recommended by the American Diabetes Association 1, 3
Meglitinides should be reassessed for hypoglycemia risk when combined with insulin, as recommended by the American Diabetes Association 1

Insulin dosing should start with basal insulin at 10 units daily or 0.1-0.2 units/kg/day while maintaining sitagliptin, as recommended by the American Diabetes Association 1, 2

A multicenter randomized controlled trial found that sitagliptin alone or combined with basal insulin achieved similar glycemic control to basal-bolus insulin regimens, with significantly fewer total insulin injections required, and no difference in hypoglycemia rates between groups, as published in Diabetes Care 4
The trial also found that there was no difference in treatment failures or length of hospital stay between the groups, as published in Diabetes Care 4

The outdated practice of stopping all oral medications when starting insulin is not evidence-based, and may lead to suboptimal glycemic control, as recommended by the American Diabetes Association 1
Premixed insulins should be avoided as they increase hypoglycemia risk threefold compared to basal-bolus regimens with analogs, as published in Diabetes Care 4
Insulin initiation should not be delayed in patients with severe hyperglycemia, as recommended by the American Diabetes Association 2, 5

Sitagliptin is particularly valuable in elderly patients due to its low hypoglycemia risk, as published in Diabetes Care 4