November 5, 2014
Initial Metformin Prescription Lowers Risk of Needing Additional Diabetes Drugs 

Boston—Starting newly diagnosed diabetes patients on metformin to lower glucose levels reduces the likelihood that a second oral medicine or insulin will be required, compared to initial treatment with sulfonylureas, thiazolidinediones or dipeptidyl peptidase 4 inhibitors (DPP-4 inhibitors), according to a new study.

Metformin is the initial treatment of choice of the American Diabetes Association, the American College of Physicians and guidelines commissioned by the Agency for Healthcare Research and Quality, according to background in the article, published recently in JAMA Internal Medicine.

The study, led by researchers from Brigham and Women’s Hospital and Harvard Medical School, compared the initial choice of a glucose-lowering medication with the time to subsequent treatment intensification, also looking at rates of hypoglycemia, diabetes-related emergency department visits or cardiovascular events. Data was pulled from records of 15,516 insured patients who had been prescribed an oral glucose-lowering medication from July 2009 through June 2013.

Slightly more than half of the patients, 57.8%, began diabetes treatment with metformin, with sulfonylurea therapy initiated in 23%, DPP-4 inhibitors in 13.1% and thiazolidinediones in 6.1%.

Results indicated that patients prescribed metformin were less likely to require treatment intensification compared to those who used the other medications. A second oral medication was required in 37.1% of patients prescribed a sulfonylurea, 39.6% prescribed a thiazolidinedione and 36.2% prescribed a DPP-4 inhibitor, compared to just 24.5% of the metformin patients.

Insulin eventually was added to 5.1% of patients prescribed metformin, 9.1% prescribed a sulfonylurea, 6.2% prescribed thiazolidinediones, and 5.6% prescribed a DPP-4 inhibitor.
Using metformin alternatives was not associated with reduced risk of hypoglycemia, emergency department visits, or cardiovascular events, according to the report, which noted that sulfonylurea initiation appeared to be associated with an increased risk of cardiovascular events.

“Despite guidelines, only 57.8% of individuals began diabetes treatment with metformin,” study authors conclude. “Beginning treatment with metformin was associated with reduced subsequent treatment intensification, without differences in rates of hypoglycemia or other adverse clinical events. These findings have significant implications for quality of life and medication costs.”

In a related commentary, Jodi B. Segal, MD, MPH, and Nisa M. Maruthur, MD, MHS, of Johns Hopkins University School of Medicine in Baltimore said the study adds only “modestly” to current information.

“Existing evidence is strong on the use of metformin as first-line therapy,” they point out.

“Although it is true in some patients that the need to add an additional medication is due to their imperfect adherence to diet and exercise or adherence to the first prescribed drug, in many other patients it reflects the expected progression of disease and worsening insulin sensitivity and declining Beta-cell function …” Segal and Maruther write, adding, ‘“Reframing the addition of medication as a necessary step for wellness and health maintenance may go a long way toward patient acceptance of intensification as an unfortunate but necessary part of good self-care.”

U.S. Pharmacist Social Connect