Use this medicine as directed even if you feel well and do not notice any signs of high blood sugar. Do not take more of this medicine and do not take it more often than your doctor ordered. To do so may increase the chance of serious side effects. Remember that this medicine will not cure your diabetes, but it does help control it. Therefore, you must continue to take it as directed if you expect to lower your blood sugar and keep it low. You may have to take an antidiabetic medicine for the rest of your life. If high blood sugar is not treated, it can cause serious problems, such as heart failure, blood vessel disease, eye disease, or kidney disease.

Your doctor will give you instructions about diet, exercise, how to test your blood sugar, and how to adjust your dose when you are sick.

• Blood sugar tests: Testing for blood sugar is the best way to tell whether your diabetes is being controlled properly. Blood sugar testing helps you and your health care team adjust your antidiabetic medicine dose, meal plan, and exercise schedule.
• Diet: The daily number of calories in your meal plan should be adjusted by your doctor or a registered dietitian to help you reach and maintain a healthy body weight. In addition, regular meals and snacks are arranged to meet the energy needs of your body at different times of the day. It is very important that you carefully follow your meal plan.
• Exercise: Ask your doctor what kind of exercise to do, the best time to do it, and how much you should do each day.
• Fluid (water) replacement: It is important to replace the water or fluid that your body uses. Tell your doctor if you have less urine output than usual or severe diarrhea that lasts for more than 1 day.
• On sick days:
  • When you become sick with a cold, fever, or the flu, you need to take your usual dose of metformin, even if you feel too ill to eat. This is especially true if you have nausea, vomiting, or diarrhea. Infection usually increases your need to produce more insulin. Sometimes you may need to be switched from metformin to insulin for a short period of time while you are sick to properly control blood sugar. Call your doctor for specific instructions, especially if severe or prolonged vomiting occurs .
  • Continue taking your metformin and try to stay on your regular meal plan. If you have trouble eating solid food, drink fruit juices, nondiet soft drinks, or clear soups, or eat small amounts of bland foods. A dietitian or your health care professional can give you a list of foods and the amounts to use for sick days.
  • Test your blood sugar and check your urine for ketones. If ketones are present, call your doctor at once. Even when you start feeling better, let your doctor know how you are doing.

Dosing

The dose of metformin will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of metformin. If your dose is different, do not change it unless your doctor tells you to do so.

The number of tablets that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the amount of sugar in your blood or urine.

• For oral dosage form (tablets):
  • For type 2 diabetes:
    • For patients taking metformin tablets
    • Adults:
      • Metformin alone: At first, 500 milligrams (mg) two times a day taken with the morning and evening meals. Or, 850 mg a day taken with the morning meal. Then, your doctor may increase your dose a little at a time every week or every other week if needed. Later, your doctor may want you to take 500 or 850 mg two to three times a day with meals.
      • Metformin with a sulfonylurea: Your doctor will determine the dose of each medicine.
      • Metformin with insulin: At first, 500 mg a day. Then, your doctor may increase your dose by 500 mg every week if needed.
    • Children up to 10 years of age Use and dose must be determined by your doctor.
    • Children 10 years of age and over At first, 500 milligrams (mg) with your morning meal and 500 mg with your evening meal. Then, your doctor may increase your dose a little at a time every week if needed.
    • For patients taking metformin extended-release tablets
    • Adults and teenagers:
      • Metformin alone: At first, 500 milligrams (mg) once daily with the evening meal. Then, your doctor may increase your dose a little at a time every week if needed. If you need more medicine, your doctor may tell you to take more than one dose a day.
      • Metformin with a sulfonylurea: Your doctor will determine the dose of each medicine.
      • Metformin with insulin: At first, 500 mg a day. Then, your doctor may increase your dose by 500 mg every week if needed.
    • Children up to 17 years of age Use and dose must be determined by your doctor.

Missed dose

If you miss a dose of this medicine, take it as soon as possible. However, if it is almost time for your next dose, skip the missed dose and go back to your regular dosing schedule. Do not double doses.

Storage

To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Keep the medicine from freezing. Do not refrigerate.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For metformin, the following should be considered:

Allergies Tell your doctor if you have ever had any unusual or allergic reaction to metformin. Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy Metformin has not been shown to cause birth defects or other problems in humans. However, metformin is not used during pregnancy. Instead, your doctor may want to control your blood sugar by diet or by a combination of diet and insulin. It is especially important for your health and your baby's health that your blood sugar be closely controlled. Close control of your blood sugar can reduce the chance of your baby gaining too much weight, having birth defects, or having high or low blood sugar. Be sure to tell your doctor if you plan to become pregnant or if you think you are pregnant.

Breast-feeding It is not known whether metformin passes into human breast milk. Although most medicines pass into breast milk in small amounts, many of them may be used safely while breast-feeding. Mothers who are taking this medicine and who wish to breast-feed should discuss this with their doctor.

Children Metformin tablets have been tested in children older than 10 years old and, in effective doses, have not been shown to cause different side effects or problems than it does in adults.

Studies with metformin extended-release tablets have been done only in adult patients, and there is no specific information comparing use of this medicine in children with use in other age groups.

Studies with metformin extended-release tablets have not been done in patients younger than 17 years old.

Older adults Use in older adults is similar to use in adults of younger age. However, if you have blood vessel disorders or kidney problems, your health care professional may adjust your dose or tell you to stop taking this medicine, if necessary.

Other medicines Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. Do not take any other medicine unless prescribed or approved by your doctor . When you are taking metformin, it is especially important that your health care professional know if you are taking any of the following:

• Alcohol Small amounts of alcohol taken with meals do not usually cause a problem; however, either larger amounts of alcohol taken for a long time or a large amount of alcohol taken in one sitting without food can increase the effect of metformin. This can keep the blood sugar low for a longer period of time than normal

• Amiloride (e.g., Midamor) or
• Calcium channel blocking agents (amlodipine [e.g., Norvasc], bepridil [e.g., Bepadin], diltiazem [e.g., Cardizem], felodipine [e.g., Plendil], flunarizine [e.g., Sibelium], isradipine [e.g., DynaCirc], nicardipine [e.g., Cardene], nifedipine [e.g., Procardia], nimodipine [e.g., Nimotop], verapamil [e.g., Calan]) or
• Cimetidine (e.g., Tagamet) or
• Digoxin (heart medicine) or
• Furosemide (e.g., Lasix) or
• Morphine (e.g., M S Contin) or
• Procainamide (e.g., Pronestyl) or
• Quinidine (e.g., Quinidex) or
• Quinine (malaria medicine) or
• Ranitidine (e.g., Zantac) or
• Triamterene (e.g., Dyrenium) or
• Trimethoprim (e.g., Proloprim) or
• Vancomycin (e.g., Vancocin) Use with metformin may cause high blood levels of metformin, which may increase the chance of low blood sugar or side effects

• Acid in the blood (ketoacidosis or lactic acidosis) or
• Burns (severe) or
• Dehydration or
• Diarrhea (severe) or
• Female hormone changes for some women (e.g., during puberty, pregnancy, or menstruation) or
• Fever, high or
• Infection (severe) or
• Injury (severe) or
• Ketones in the urine or
• Mental stress (severe) or
• Overactive adrenal gland (not properly controlled) or
• Problems with intestines (severe) or
• Slow stomach emptying or
• Surgery (major) or
• Vomiting or
• Any other condition that causes problems with eating or absorbing food or
• Any other condition in which blood sugar changes rapidly Metformin in many cases will be replaced with insulin by your doctor, possibly only for a short time. Use of insulin is best to help control diabetes mellitus in patients with these conditions that without warning cause quick changes in the blood sugar.

• Heart or blood vessel disorders or
• Kidney disease or kidney problems or
• Liver disease (or history of) Lactic acidosis can occur in these conditions and chances of it occurring are even greater with use of metformin

• Kidney, heart, or other problems that require medical tests or examinations that use certain medicines called contrast agents, with x-rays Metformin should be stopped before medical exams or diagnostic tests that might cause less urine output than usual. Passing unusually low amounts of urine may increase the chance of a build-up of metformin and unwanted effects. Metformin may be restarted 48 hours after the exams or tests if kidney function is tested and found to be normal

• Overactive thyroid (not properly controlled) or
• Underactive thyroid (not properly controlled) Until the thyroid condition is controlled, it may change the amount or type of antidiabetic medicine you need

• Underactive adrenal gland (not properly controlled) or
• Underactive pituitary gland (not properly controlled) or
• Undernourished condition or
• Weakened physical condition or
• Any other condition that causes low blood sugar Patients who have any of these conditions may be more likely to develop low blood sugar, which can affect the dose of metformin you need and increase the need for blood sugar testing