Comparative evaluation of incretin‐based antidiabetic medications and alternative therapies to be added to metformin in the case of monotherapy failure

Aims/Introduction: To compare clinical consequences of using inretin‐based medications versus conventional antidiabetic agents as add‐on to metformin in case of monotherapy failure in patients with type 2 diabetes. Materials and Methods: The medical literature including recent abstracts from international diabetes conferences was searched for reports from clinical trials with incretin mimetics (GLP‐1 receptor agonists), inhibitors of dipeptidyl peptidase‐4 (DPP‐4, incretin enhancers) and conventional antidiabtic drugs coadministered with metformin after monotherapy failure. A scoring system is suggested to compare the clinical utility of using incretin‐based versus conventional antidiabetic agents in this situation. Results: Incretin mimetics and DPP‐4 inhibitors on top of metformin treatment help achieve glycaemic control comparable to other efficient antidiabetic drugs, both if separate or head‐to‐head trials were considered. Incretin‐based antidiabetic drugs did not cause hypoglycaemia (different from sulfonylureas, meglitinides and insulin) and weight gain (different from sulfonylureas, meglitinides, thiazolidinediones, and insulin). DPP‐4 inhibitors were weight neutral, incretin mimetics lead to weight loss. The clinical profile of incretin‐based medications received the highest scores, followed by α‐glucosidase inhibitors, with far lower scores assigned to insulin, glitazones, and sulfonyureas (in this order). Conclusions: Based on the results from clinical trials, incretin‐based medications have been shown to be efficacious antidiabetic drugs with a favourable adverse event and tolerability profile. This leads to high scores using a novel system paying attention to multiple facets contributing to the selection of antidiabetic drugs for general recommendation and individual treatment choices.