Sulfonylureas Are as Effective As Newer Diabetic Agents at a Lower Cost
Sulfonylureas are as effective as dipeptidyl peptidase-4 (DDP-4) inhibitors and glucagon-like peptide-1 (GLP-1) receptor agonists as second-line treatments for type 2 diabetes but at a lower cost, according to a study in February 26 issue of Diabetes Care.
"Conventional wisdom would suggest that newer medications should be more effective since they cost more, but what we find is that they don't appear to result in people living longer or avoiding complications," said lead author Brian Denton, PhD, Associate Professor of Industrial and Operations Engineering, at the University of Michigan, Ann Arbor.
“This is an important study because it addresses a very important question: what is the best second drug to add to metformin in patients with type 2 diabetes who don’t get to goal,” commented Elizabeth Seaquist, MD, President, Medicine & Science of the American Diabetes Association. “In fact, it is such an important question that the National Institutes of Health is funding a large trial called GRADE (Glycemia Reduction Approaches in Diabetes) that is actually prospectively examining this question. When that study comes out we will have much more definitive information about which drug is the best to add to metformin,” Dr. Seaquist said.
Design of the Simulation Model
The findings are based on a simulation model involving 15 years worth of claims data from more than 37,000 patients. Four treatment intensification models were evaluated. All of the models included metformin monotherapy with the addition of one of the following four second-line agents when a patient’s A1c level reached a prespecified level: DPP-4 inhibitors, GLP-1 agonists, sulfonylurea, or insulin. Patients given one of the non-insulin agents as second-line therapy were switched to insulin (plus metformin) when A1c levels again exceeded a prespecified glycemic level. The model took into account adverse effects of treatments (including hypoglycemia), medication cost, and various glycemic control goals.
All four treatments resulted in similar benefits in expected life years from diagnosis to the first development of a major diabetes-related complication and quality-adjusted life-years (QALY) to the first event. However, expected medication cost per QALY was significantly lower with sulfonylurea than with the other medications and was linked to the longest time to insulin dependence.
The lower cost of sulfonylureas is not surprising considering that this class of medication is available generically, while most of the other medications are not, Dr. Seaquist commented.
“All of the medications that have been considered in the model have some risk and down sides that can impact a person's well-being," said coauthor Steven Smith, MD, endocrinologist and Professor of Medicine at Mayo Clinic, Rochester, MN. "But our model can help to assess optimal decision-making that would take into account individual and unique risks for all medications, old and new."
The authors suggested that, in the future, their model may be a useful adjunctive decision aid for selecting treatments in patients with newly diagnosed type 2 diabetes.
“Whenever you are looking at data sets like this we don’t know why one drug was chosen versus another and so there may be something specific about a patient who was prescribed a sulfonylurea that is different from a patient who was prescribed a DPP-4 inhibitor that could be important in the outcome measure used in this study,” Dr. Seaquist noted.