Most people who have had lactic acidosis with metformin have other things that, combined with the metformin, led to the lactic acidosis. Tell your doctor if you have any of the following, because you have a higher chance of getting lactic acidosis with JANUMET or JANUMET XR if you: have severe kidney problems or your kidneys are affected by certain x-ray tests that use injectable dye; have liver problems; drink alcohol very often, or drink a lot of alcohol in short-term “binge” drinking; get dehydrated (lose large amounts of body fluids, which may happen if you are sick with fever, vomiting, or diarrhea; if you sweat a lot with activity or exercise and do not drink enough fluids); have surgery; have a heart attack, severe infection, stroke, or are 65 years of age or older. Your doctor may decide to stop your JANUMET or JANUMET XR for a while if you have any of these things.