Rosiglitazone and metformin, a medication available by prescription, is used to treat type 2 diabetes in adults. It helps reduce blood sugar levels by decreasing sugar absorption into the body and improving insulin sensitivity. Rosiglitazone and metformin, which should be used in conjunction with lifestyle changes, comes in a tablet form that is usually taken once or twice a day. The combination drug is not suitable for everyone, so let your healthcare provider know if you have any heart problems, kidney problems, or liver problems.