Metformin - commercially available as Glucophage - is a popular diabetes drug that works by making the body more responsive to insulin. On the other hand, sitagliptin or the Merck diabetes drug Januvia™ works to boost the body's ability to lower elevated blood sugar levels.

When combined together in people with type 2 diabetes, sitagliptin and metformin improves blood sugar control in a synergistic fashion, according to a new study by Merck Research Laboratories.

"This was significantly better than results with a single drug and "demonstrated an additive response." There was a low incidence of hypoglycemia, or low blood sugar, which was not significantly different from that in the placebo group.

This study shows that the combination of sitagliptin and metformin provides "substantial and additive" improvement in blood sugar levels and is "generally well tolerated."

Find more details from Merck News.