Metformin Er 500 Mg

Some tablets are made with a shell that is not absorbed or melted in the body. Part of this shell may appear in your stool. This is normal and will not make the medicine less effective.

Metformin Extended Release Tablets Prescribing Information

Medically reviewed by Drugs.com. Last updated on Feb 1, 2023.

On This Page

• Warnings
• Indications and Usage
• Precautions
• Drug Interactions
• Overdosage

HOW TO USE THIS INFORMATION: This is a summary and does NOT have all possible information about this product. This information does not assure that this product is safe, effective, or appropriate for you. This information is not individual medical advice and does not substitute for the advice of your health care professional. Always ask your health care professional for complete information about this product and your specific health needs.

METFORMIN SUSTAINED-ACTION TABLET – ORAL (met-FOR-min)
COMMON BRAND NAME(S): Fortamet, Glucophage XR, Glumetza

WARNING:

Metformin can rarely cause a serious (sometimes fatal) condition called lactic acidosis. Stop taking metformin and get medical help right away if you develop any of the following symptoms of lactic acidosis: unusual tiredness, dizziness, severe drowsiness, chills, blue/cold skin, muscle pain, fast/difficult breathing, slow/irregular heartbeat, stomach pain with nausea, vomiting, or diarrhea. Lactic acidosis is more likely to occur in patients who have certain medical conditions, including kidney or liver disease, recent surgery, a serious infection, conditions that may cause a low level of oxygen in the blood or poor circulation (such as congestive heart failure, recent heart attack, recent stroke), heavy alcohol use, a severe loss of body fluids (dehydration), or X-ray or scanning procedures that require an injectable iodinated contrast drug. Tell your doctor immediately if any of these conditions occur or if you notice a big change in your overall health. You may need to stop taking this medication temporarily. The elderly are also at higher risk, especially those older than 80 years who have not had kidney tests. (See also Side Effects and Precautions sections.)

USES:

Metformin is used with a proper diet and exercise program and possibly with other medications to control high blood sugar. It is used in patients with type 2 diabetes (non-insulin-dependent diabetes). Controlling high blood sugar helps prevent kidney damage, blindness, nerve problems, loss of limbs, and sexual function problems. Proper control of diabetes may also lessen your risk of a heart attack or stroke. Metformin works by helping to restore your body’s proper response to the insulin you naturally produce. It also decreases the amount of sugar that your liver makes and that your stomach/intestines absorb.

Interestingly, Americans show more favor toward Medicare for All healthcare initiatives than they do toward these efforts when they are labeled as “single payer,” most likely due to the popularity of the Medicare program, STAT

OTHER USES:

This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional. Metformin may be used with lifestyle changes such as diet and exercise to prevent diabetes in people who are at high risk for becoming diabetic. It is also used in women with a certain disease of the ovaries (polycystic ovarian syndrome). Metformin may make menstrual cycles more regular and increase fertility.

HOW TO USE:

Read the Patient Information Leaflet if available from your pharmacist before you start taking metformin and each time you get a refill. If you have any questions, consult your doctor or pharmacist. Take this medication by mouth as directed by your doctor, usually once daily with the evening meal. Drink plenty of fluids while taking this medication unless otherwise directed by your doctor. Do not crush or chew this medication. Doing so can release all of the drug at once, increasing the risk of side effects. Also, do not split the tablets unless they have a score line and your doctor or pharmacist tells you to do so. Swallow the whole or split tablet without crushing or chewing. The dosage is based on your medical condition, kidney function, and response to treatment. Your doctor may direct you to take a low dose of this medication at first, gradually increasing your dose to lower the chance of side effects such as upset stomach. Your doctor will adjust your dose based on your blood sugar levels to find the best dose for you. Follow your doctor’s directions carefully. Take this medication regularly in order to get the most benefit from it. Remember to use it at the same time each day. If you are already taking another anti-diabetic drug (such as chlorpropamide), follow your doctor’s directions carefully for stopping/continuing the old drug and starting metformin. Check your blood sugar regularly as directed by your doctor. Keep track of the results, and share them with your doctor. Tell your doctor if your blood sugar measurements are too high or too low. Your dosage/treatment may need to be changed.

SIDE EFFECTS:

Nausea, vomiting, stomach upset, diarrhea, weakness, or a metallic taste in the mouth may occur. If any of these effects persist or worsen, tell your doctor or pharmacist promptly. If stomach symptoms return later (after taking the same dose for several days or weeks), tell your doctor immediately. Stomach symptoms that occur after the first days of your treatment may be signs of lactic acidosis. An empty tablet shell may appear in your stool. This effect is harmless because your body has already absorbed the medication. Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects. Metformin does not usually cause low blood sugar (hypoglycemia). Low blood sugar may occur if this drug is prescribed with other anti-diabetic medications. Talk with your doctor or pharmacist about whether the dose of your other diabetic medication(s) needs to be lowered. Symptoms of low blood sugar include sudden sweating, shaking, fast heartbeat, hunger, blurred vision, dizziness, or tingling hands/feet. It is a good habit to carry glucose tablets or gel to treat low blood sugar. If you don’t have these reliable forms of glucose, rapidly raise your blood sugar by eating a quick source of sugar such as table sugar, honey, or candy, or drink fruit juice or non-diet soda. Tell your doctor about the reaction immediately. Low blood sugar is more likely if you drink large amounts of alcohol, do unusually heavy exercise, or do not consume enough calories from food. To help prevent low blood sugar, eat meals on a regular schedule, and do not skip meals. Check with your doctor or pharmacist to find out what you should do if you miss a meal. Symptoms of high blood sugar (hyperglycemia) include thirst, increased urination, confusion, drowsiness, flushing, rapid breathing, and fruity breath odor. If these symptoms occur, tell your doctor immediately. Your doctor may need to adjust your diabetes medication(s). Stop taking this medication and tell your doctor right away if this very serious side effect occurs: lactic acidosis (see Warning section). A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any of the following symptoms of a serious allergic reaction: rash, itching/swelling (especially of the face/tongue/throat), severe dizziness, trouble breathing. This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist. In the US – Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088. In Canada – Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.

PRECAUTIONS:

See also Warning section. Before taking this medication, tell your doctor or pharmacist if you are allergic to metformin; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this medication, tell your doctor or pharmacist your medical history, especially of: severe breathing problems (such as obstructive lung disease, severe asthma), metabolic acidosis (such as diabetic ketoacidosis), blood problems (such as anemia, vitamin B12 deficiency), kidney disease, liver disease. Before having surgery or any X-ray/scanning procedure using injectable iodinated contrast material, tell your doctor that you are taking this medication. You will need to temporarily stop this medication before the time of your surgery/procedure. Consult your doctor for further instructions. Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). You may experience blurred vision, dizziness, or drowsiness due to extremely low or high blood sugar levels. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely. Limit alcohol while using this medication because it can increase your risk of lactic acidosis and developing low blood sugar. High fever, “water pills” (diuretics such as hydrochlorothiazide), too much sweating, diarrhea, or vomiting may cause loss of too much body water (dehydration) and increase your risk of lactic acidosis. Stop taking this medication and tell your doctor right away if you have prolonged diarrhea or vomiting. Be sure to drink enough fluids to prevent dehydration unless your doctor directs you otherwise. It may be harder to control your blood sugar when your body is stressed (such as due to fever, infection, injury, or surgery). Consult your doctor because increased stress may require a change in your treatment plan, medications, or blood sugar testing. Older adults may be a greater risk for side effects such as low blood sugar or lactic acidosis. During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor. Your doctor may direct you to use insulin instead of this product during your pregnancy. Follow your doctor’s instructions carefully. Metformin can cause changes in the menstrual cycle (promote ovulation) and increase the risk of becoming pregnant. Consult your doctor or pharmacist about the use of reliable birth control while using this medication. Metformin passes into breast milk in small amounts. Consult your doctor before breast-feeding.

DRUG INTERACTIONS:

Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor’s approval. Many drugs can affect your blood sugar levels, making it more difficult to control your blood sugar. Before you start, stop, or change any medication, talk with your doctor or pharmacist about how the medication may affect your blood sugar. Check your blood sugar levels regularly as directed by your doctor. Tell your doctor about the results and of any symptoms of high or low blood sugar. (See also Side Effects section.) Your doctor may need to adjust your anti-diabetic medication, exercise program, or diet.

OVERDOSE:

If overdose is suspected, contact a poison control center or emergency room immediately. US residents can call the US National Poison Hotline at 1-800-222-1222. Canada residents can call a provincial poison control center. Overdose can cause lactic acidosis. Symptoms of overdose may include: severe drowsiness, severe nausea/vomiting/diarrhea, rapid breathing, slow/irregular heartbeat.

NOTES:

Do not share this medication with others. You should attend a diabetes education program to learn more about diabetes and all the important aspects of its treatment, including meals/diet, exercise, personal hygiene, medications, and getting regular eye/foot/medical exams. Keep all medical appointments. Laboratory and/or medical tests (such as liver/kidney function tests, blood glucose, hemoglobin A1c, complete blood counts) should be performed periodically to check for side effects and monitor your response to treatment. Check your blood sugar levels regularly as directed.

MISSED DOSE:

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.

STORAGE:

Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets. Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.

MEDICAL ALERT:

Your condition can cause complications in a medical emergency. For information about enrolling in MedicAlert, call 1-800-854-1166 (US) or 1-800-668-1507 (Canada).

Manufactured by Tagi Pharamaceuticals

Distributed by: Calvin Scott & Co., Inc. Albuquerque, NM 87123. (800)-545-6545

Information last revised March 2012. Copyright(c) 2012 First Databank, Inc.

Package Labeling:

Calvin Scott & Co., Inc.

Frequently asked questions

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Patient resources

Professional resources

• Prescribing Information
• Metformin (FDA)
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• Metformin Extended Release Tablet (FDA)
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Metformin

Medically reviewed by Melisa Puckey, BPharm. Last updated on Apr 5, 2023.

What is metformin?

Metformin is an FDA-approved antidiabetic agent that manages high blood sugar levels in type 2 diabetes patients. It reduces glucose absorption from the intestines, lowers liver glucose production, and improves insulin sensitivity. Metformin is recommended with dietary changes and exercise for better results.

Managing blood sugar levels with medications like metformin can prevent complications such as kidney damage, nerve issues, blindness, amputations, and sexual dysfunction. Effective diabetes control can also lower the risk of heart attacks or strokes.

Warnings

You should not use metformin if you have severe kidney disease, metabolic acidosis, or diabetic ketoacidosis (call your doctor for treatment).

If you need to have any type of x-ray or CT scan using a dye that is injected into your veins, you may need to temporarily stop taking metformin.

Though extremely rare, you may develop lactic acidosis, a dangerous build-up of lactic acid in your blood. Call your doctor or get emergency medical help if you have unusual muscle pain, trouble breathing, stomach pain, dizziness, feeling cold, or feeling very weak or tired.

Before taking this medicine

You should not use metformin if you are allergic to it, or if you have:

• severe kidney disease; or
• metabolic acidosis or diabetic ketoacidosis (call your doctor for treatment).

If you need to have surgery or any type of x-ray or CT scan using a dye that is injected into your veins, you may need to temporarily stop taking metformin. Be sure your caregivers know ahead of time that you are using this medication.

Tell your doctor if you have ever had:

• kidney disease (your kidney function may need to be checked before you take this medicine);
• high ketone levels in your blood or urine;
• heart disease, congestive heart failure;
• liver disease; or
• if you also use insulin, or other oral diabetes medications.

You may develop lactic acidosis, a dangerous build-up of lactic acid in your blood. This may be more likely if you have other medical conditions, a severe infection, chronic alcoholism, or if you are 65 or older. Ask your doctor about your risk.

Follow your doctor’s instructions about using metformin if you are pregnant or you become pregnant. Controlling diabetes is very important during pregnancy, and having high blood sugar may cause complications in both the mother and the baby. Tell your doctor if you become pregnant while taking metformin.

Metformin may stimulate ovulation in a premenopausal woman and may increase the risk of unintended pregnancy. Talk to your doctor about your risk.

You should not breastfeed while using this medicine.

Metformin should not be given to a child younger than 10 years old. Some forms of metformin are not approved for use by anyone younger than 18 years old.

How should I take metformin?

Take metformin exactly as prescribed by your doctor. Follow all directions on your prescription label and read all medication guides or instruction sheets. Your doctor may occasionally change your dose. Use the medicine exactly as directed.

Take metformin with a meal, unless your doctor tells you otherwise. Some forms of metformin are taken only once daily with the evening meal. Follow your doctor’s instructions.

Do not crush, chew, or break an extended-release tablet. Swallow it whole.

Measure liquid medicine carefully. Shake the oral suspension before you measure a dose. Use the dosing syringe provided, or use a medicine dose-measuring device (not a kitchen spoon).

Some tablets are made with a shell that is not absorbed or melted in the body. Part of this shell may appear in your stool. This is normal and will not make the medicine less effective.

You may have low blood sugar (hypoglycemia) and feel very hungry, dizzy, irritable, confused, anxious, or shaky. To quickly treat hypoglycemia, eat or drink a fast-acting source of sugar (fruit juice, hard candy, crackers, raisins, or non-diet soda).

Your doctor may prescribe a glucagon injection kit in case you have severe hypoglycemia. Be sure your family or close friends know how to give you this injection in an emergency.

Blood sugar levels can be affected by stress, illness, surgery, exercise, alcohol use, or skipping meals. Ask your doctor before changing your dose or medication schedule.

Metformin is only part of a complete treatment program that may also include diet, exercise, weight control, regular blood sugar testing, and special medical care. Follow your doctor’s instructions very closely.

Store at room temperature away from moisture, heat, and light.

Your doctor may have you take extra vitamin B12 while you are taking this medicine. Take only the amount of vitamin B12 that your doctor has prescribed.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222. An overdose can cause severe hypoglycemia or lactic acidosis.

What to avoid

Avoid drinking alcohol. It lowers blood sugar and may increase your risk of lactic acidosis.

Metformin side effects

Get emergency medical help if you have signs of an allergic reaction to metformin: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Some people using this medicine develop lactic acidosis, which can be fatal. Get emergency medical help if you have even mild symptoms such as:

• unusual muscle pain;
• feeling cold;
• trouble breathing;
• feeling dizzy, light-headed, tired, or very weak;
• stomach pain, vomiting; or
• slow or irregular heart rate.

Common metformin side effects may include:

• low blood sugar;
• nausea, upset stomach; or
• diarrhea.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect metformin?

Many drugs can interact with metformin, making it less effective or increasing your risk of lactic acidosis. This includes prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible interactions are listed here. Tell your doctor about all your current medicines and any medicine you start or stop using.

Popular FAQ

Most experts consider metformin to be the safest medicine for type 2 diabetes because it has been used for many decades, is effective, affordable, and safe. Metformin is recommended as a first-line treatment for type 2 diabetes by the American Diabetes Association (ADA). Continue reading

Metformin, an oral type 2 diabetes medicine, may lead to a modest weight loss and does not usually lead to significant, if any, weight gain. In various clinical studies, when metformin was used alone, it led to a weight loss of 0.7 to 3.8 kg (1.5 to 8.4 lbs) in most patients, but other studies have shown weight loss up to 5.8 kg (12.8 lbs). Continue reading

Metformin rarely produces hypoglycemia (low blood sugar levels) because it does not change how much insulin is secreted by the pancreas and does not cause high insulin levels. But metformin toxicity or overdosage that causes lactic acidosis has been associated with hypoglycemia. Experts believe the cause may be increased glucose consumption due to anaerobic metabolism, coupled with decreased oral intake of food and carbohydrates, decreased liver glucose production, and decreased glucose absorption. Continue reading

More FAQ

• Is Invokana the same as metformin?
• How long does glucophage/Metformin stay in your system?
• Can Diabetes go away?

More about metformin

• Check interactions
• Compare alternatives
• Pricing & coupons
• Reviews (635)
• Drug images
• Latest FDA alerts (18)
• Side effects
• Dosage information
• Patient tips
• During pregnancy
• Support group
• Drug class: non-sulfonylureas
• Breastfeeding