A 78-year-old man comes to your office to discuss the optimization of his medications. He has type 2 diabetes and chronic renal failure. With his current medication regimen, he has noticed that he has less of an appetite and, as a result, has lost 20 pounds over the past year. His renal function has been declining steadily over the past year. On examination, he appears fairly thin and frail. You would like to consider switching him to an antidiabetic agent that, in addition to reducing blood glucose levels, may promote weight gain as a side effect and is safe to use in chronic renal failure. Which of the following agents would you choose?
