US regulators have cleared the use of a once-daily formulation of Boehringer Ingelheim and Eli Lilly's diabetes drug Synjardy.

Synjardy XR is a combination of empagliflozin and metformin indicated to improve blood glucose in adults with type II diabetes.

Empagliflozin, a sodium-glucose co-transporter 2 inhibitor, removes excess glucose through the urine by blocking glucose re-absorption in the kidney, while metformin lowers glucose production by the liver and its absorption in the intestine.

"Adults with type II diabetes often take multiple medications, sometimes more than once a day, to manage their condition," said Paul Fonteyne, president and chief executive of Boehringer Ingelheim Pharmaceuticals.

"With Synjardy XR, the eighth FDA-approved treatment to emerge from our partnership with Lilly, adults with type 2 diabetes now have another convenient daily option to help them reach their glycaemic goals, whether they are already being treated or are just at the beginning of their treatment."

The approval comes on the back of results from multiple clinical trials showing the drug's efficacy in the treatment of adults with the condition.

On the downside, the combination can cause serious side effects, including lactic acidosis, a rare, but serious condition that can cause death, as well as dehydration, low blood pressure and increased ketones in the blood.