Janumet, a tablet combining the new diabetes drug Januvia (sitagliptin) and the old diabetes drug metformin, was approved by the FDA on April 2nd for treatment of type 2 diabetes.

The FDA approved Janumet, as an adjunct to diet and exercise, to improve blood sugar (glucose) control in patients with type 2 diabetes who are not adequately controlled on metformin or sitagliptin alone, or in patients already treated with the combination of Januvia and metformin.

Merck said it compared Janumet to metformin in a six-month study of 701 diabetics whose blood sugar was mildly to moderately elevated despite taking metformin.

More than twice as many patients taking Janumet got their hemoglobin A1c level (the best measure of long-term blood glucose control) into the recommended range as those taking metformin alone.

The risk of low blood sugar (hypoglycemia), swelling, and gastrointestinal side effects was similar in the Janumet and metformin-only groups, Merck said.

Janumet shouldn't be taken by patients with conditions including liver disease, renal (kidney) disease, renal dysfunction, type 1 diabetes, or a complication of diabetes called diabetic ketoacidosis.