Metformin (Systemic)

Brand Names : Glucophage, Glucophage XR, Apo-Metformin, Gen-Metformin, Glycon, Novo-Metformin, Nu-Metformin

Before Using This Medicine

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.

Adolescents - Metformin tablets have been tested in teenagers older than 17 years and, in effective doses, have not been shown to cause different side effects or problems than in adults.

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

Other medical problems - The presence of other medical problems may affect the use of metformin. Make sure you tell your doctor if you have any other medical problems, especially:

• 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