Possible Glucophage Side Effects: Also see WARNING. SIDE EFFECTS, that may go away during treatment, include metallic taste in mouth, nausea, stomach upset, and diarrhea. If they continue or are bothersome, check with your doctor. If stomach symptoms recur later (after you are on the same dose for several days or weeks), tell your doctor immediately. A late recurrence of stomach symptoms may be due to a serious medical condition (lactic acidosis). This medicine usually does not cause low blood sugar (hypoglycemia), but this effect may occur if you do not consume enough calories (from food, juices, fruit, etc.). The symptoms include chills, cold sweat, dizziness, drowsiness, shaking, rapid heartbeat, weakness, headache, fainting, tingling of the hands or feet, or hunger. It is a good habit to carry glucose tablets or gel to treat low blood sugar. If you are in a situation where you don't have these reliable forms of glucose, eat a quick source of sugar such as table sugar, honey, or candy, or drink a glass of orange juice or non-diet soda to quickly raise your blood sugar level. Tell your doctor immediately about the reaction. To help prevent hypoglycemia, eat meals on a regular schedule and do not skip meals. Symptoms of high blood sugar (hyperglycemia) include thirst, increased urination, confusion, drowsiness, flushing, rapid breathing, or fruity breath odor. If these symptoms occur, tell your doctor immediately. Your medication dosage may need to be increased. IF YOU EXPERIENCE difficulty breathing; tightness of chest; swelling of eyelids, face or lips; or if you develop a rash or hives, tell your doctor immediately. Do not take any more doses of Glucophage unless your doctor tells you to do so. If you notice other effects not listed above, contact your doctor, nurse, or pharmacist.