How Taken: For adults, metformin is usually started at the dose of 500 mg twice daily or 850 mg daily. The dose is gradually increased by 500 mg weekly or 850 mg every two weeks as tolerated and based on the response of the levels of glucose in the blood. The maximum daily dose is 2550 mg, given in three divided doses. If Glucophage XR tablets are used, the starting dose is 500 mg daily with the evening meal. The dose can be increased by 500 mg weekly up to a maximum dose of 2000 mg once daily or in two divided doses. Glumetza tablets are given once daily. Metformin should be taken with meals.
Missed Dose: Take the missed dose as soon as you remember. However, if it is almost time for the next dose, skip the missed dose and only take the next regularly scheduled dose. Do not take a double dose.
More Information: Stop taking metformin and seek emergency medical attention if you experience an allergic reaction (difficulty in breathing; closing of the throat; swelling of the lips, tongue, or face; or hives).A small number of people who have taken metformin have developed a serious condition, called lactic acidosis that has been fatal in up to 50% of cases. Lactic acidosis has occurred most often in people whose kidneys were not working properly. Liver problems may also increase the risk of developing lactic acidosis. Stop taking metformin and call your doctor immediately if you experience a feeling of general discomfort or sickness; weakness; sore or aching muscles; trouble breathing, unusual drowsiness, dizziness or lightheadedness; unusual or unexplained stomach upset (after the initial stomach upset that may occur at the start of therapy with metformin); or the sudden development of a slow or irregular heartbeat. These may be signs of lactic acidosis.Metformin does not usually cause hypoglycemia (low blood sugar). Nevertheless, hypoglycemia may occur in the treatment of diabetes, as a result of skipped meals, excessive exercise, or alcohol consumption. Know the signs and symptoms of low blood sugar, which include hunger, headache, drowsiness, weakness, dizziness, a fast heartbeat, sweating, tremor, and nausea. Carry a non-dietetic candy or glucose tablets to treat episodes of low blood sugar.Other, less serious side effects may be more likely to occur. Continue to take metformin and talk to your doctor if you experience nausea, vomiting, abdominal pain, or diarrhea at the start of therapy; abdominal bloating or increased gas production; or decreased appetite or changes in taste (metallic taste in your mouth).Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.