Metformin Hydrochloride  

Get an overview of METFORMIN HYDROCHLORIDE (metformin), including its generic name, formulation (i.e. pill, oral solution, injection, inhaled medicine) and why it’s used. The medication in Metformin Hydrochloride can be sold under different names.

Refer to the “Also Known As” section to reference different products that include the same medication as Metformin Hydrochloride.

Drug Basics

Brand Name: Metformin Hydrochloride

Generic Name: METFORMIN


Route: ORAL

Dosage Form:  

Data Current As Of: 2018-10-05

indications & usage

Metformin HCl Tablets, USP are indicated as an adjunct to diet and exercise to improve glycemic control in adults and children with type 2 diabetes mellitus.


Metformin HCl, USP is contraindicated in patients with:

  • Renal disease or renal dysfunction (e.g., as suggested by serum creatinine levels ≥1.5 mg/dL [males], ≥1.4 mg/dL [females] or abnormal creatinine clearance) which may also result from conditions such as cardiovascular collapse (shock), acute myocardial infarction, and septicemia (see WARNINGS and PRECAUTIONS ).
  • Known hypersensitivity to metformin HCl, USP.
  • Acute or chronic metabolic acidosis, including diabetic ketoacidosis, with or without coma. Diabetic ketoacidosis should be treated with insulin.

Metformin HCl, USP should be temporarily discontinued in patients undergoing radiologic studies involving intravascular administration of iodinated contrast materials, because use of such products may result in acute alteration of renal function. (See also PRECAUTIONS .)

Manufactured by:

Amneal Pharmaceuticals of NY

Hauppauge, NY 11788

Distributed by:

Amneal Pharmaceuticals

Glasgow, KY 42141

Rev. 06-2012

patient information

Metformin Hydrochloride Tablets

Read this information carefully before you start taking this medicine and each time you refill your prescription. There may be new information. This information does not take the place of your doctor’s advice. Ask your doctor or pharmacist if you do not understand some of this information or if you want to know more about this medicine.

What is Metformin HCl?

Metformin HCl is used to treat type 2 diabetes. This is also known as noninsulin- dependent diabetes mellitus. People with type 2 diabetes are not able to make enough insulin or respond normally to the insulin their bodies make. When this happens, sugar (glucose) builds up in the blood. This can lead to serious medical problems including kidney damage, amputations, and blindness. Diabetes is also closely linked to heart disease. The main goal of treating diabetes is to lower your blood sugar to a normal level.

High blood sugar can be lowered by diet and exercise, by a number of medicines taken by mouth, and by insulin shots. Before you take Metformin HCl, try to control your diabetes by exercise and weight loss. While you take your diabetes medicine, continue to exercise and follow the diet advised for your diabetes. No matter what your recommended diabetes management plan is, studies have shown that maintaining good blood sugar control can prevent or delay complications of diabetes, such as blindness.

Metformin HCl helps control your blood sugar in a number of ways. These include helping your body respond better to the insulin it makes naturally, decreasing the amount of sugar your liver makes, and decreasing the amount of sugar your intestines absorb. Metformin HCl does not cause your body to make more insulin. Because of this, when taken alone, they rarely cause hypoglycemia (low blood sugar), and usually do not cause weight gain. However, when they are taken with a sulfonylurea or with insulin, hypoglycemia is more likely to occur, as is weight gain.

WARNING: A small number of people who have taken Metformin HCl have developed a serious condition called lactic acidosis. Lactic acidosis is caused by a buildup of lactic acid in the blood. This happens more often in people with kidney problems. Most people with kidney problems should not take Metformin HCl. (See “What are the side effects of Metformin HCl?”)

Who should not take Metformin HCl?

Some conditions increase your chance of getting lactic acidosis, or cause other problems if you take either of these medicines. Most of the conditions listed below can increase your chance of getting lactic acidosis.

Do not take Metformin HCl if you:

  • have kidney problems

  • have liver problems

  • have heart failure that is treated with medicines, such as Lanoxin® (digoxin) or Lasix® (furosemide)

  • drink a lot of alcohol. This means you binge drink for short periods or drink all the time

  • are seriously dehydrated (have lost a lot of water from your body)

  • are going to have an x-ray procedure with injection of dyes (contrast agents)

  • are going to have surgery

  • develop a serious condition, such as heart attack, severe infection, or a stroke

  • are 80 years or older and you have NOT had your kidney function tested

Tell your doctor if you are pregnant or plan to become pregnant. Metformin HCl may not be right for you. Talk with your doctor about your choices. You should also discuss your choices with your doctor if you are nursing a child.

Can Metformin HCl be used in children?

Metformin HCl has been shown to effectively lower glucose levels in children (ages 10 to 16 years) with type 2 diabetes. Metformin HCl has not been studied in children younger than 10 years old. Metformin HCl has not been studied in combination with other oral glucose-control medicines or insulin in children. If you have any questions about the use of Metformin HCl in children, talk with your doctor or other healthcare provider.

How should I take Metformin HCl?

Your doctor will tell you how much medicine to take and when to take it. You will probably start out with a low dose of the medicine. Your doctor may slowly increase your dose until your blood sugar is better controlled. You should take Metformin HCl with meals.

Your doctor may have you take other medicines along with Metformin HCl to control your blood sugar. These medicines may include insulin shots. Taking Metformin HCl with insulin may help you better control your blood sugar while reducing the insulin dose.

Continue your exercise and diet program and test your blood sugar regularly while taking Metformin HCl. Your doctor will monitor your diabetes and may perform blood tests on you from time to time to make sure your kidneys and your liver are functioning normally. There is no evidence that Metformin HCl causes harm to the liver or kidneys.

Tell your doctor if you:

  • have an illness that causes severe vomiting, diarrhea or fever, or if you drink a much lower amount of liquid than normal. These conditions can lead to severe dehydration (loss of water in your body). You may need to stop taking Metformin HCl for a short time.

  • plan to have surgery or an x-ray procedure with injection of dye (contrast agent). You may need to stop taking Metformin HCl for a short time.

  • start to take other medicines or change how you take a medicine. Metformin HCl can affect how well other drugs work, and some drugs can affect how well Metformin HCl work. Some medicines may cause high blood sugar.

What should I avoid while taking Metformin HCl?

Do not drink a lot of alcoholic drinks while taking Metformin HCl. This means you should not binge drink for short periods, and you should not drink a lot of alcohol on a regular basis. Alcohol can increase the chance of getting lactic acidosis.

What are the side effects of Metformin HCl?

Lactic Acidosis. In rare cases, Metformin HCl can cause a serious side effect called lactic acidosis. This is caused by a buildup of lactic acid in your blood. This build-up can cause serious damage. Lactic acidosis caused by Metformin HCl is rare and has occurred mostly in people whose kidneys were not working normally. Lactic acidosis has been reported in about one in 33,000 patients taking Metformin HCl over the course of a year. Although rare, if lactic acidosis does occur, it can be fatal in up to half the people who develop it.

It is also important for your liver to be working normally when you take Metformin HCl. Your liver helps remove lactic acid from your blood.

Make sure you tell your doctor before you use Metformin HCl if you have kidney or liver problems. You should also stop using Metformin HCl and call your doctor right away if you have signs of lactic acidosis. Lactic acidosis is a medical emergency that must be treated in a hospital.

Signs of lactic acidosis are:

feeling very weak, tired, or uncomfortable

unusual muscle pain

trouble breathing

unusual or unexpected stomach discomfort

feeling cold

feeling dizzy or lightheaded

suddenly developing a slow or irregular heartbeat

If your medical condition suddenly changes, stop taking Metformin HCl and call your doctor right away. This may be a sign of lactic acidosis or another serious side effect.

Other Side Effects. Common side effects of Metformin HCl include diarrhea, nausea, and upset stomach. These side effects generally go away after you take the medicine for a while. Taking your medicine with meals can help reduce these side effects. Tell your doctor if the side effects bother you a lot, last for more than a few weeks, come back after they’ve gone away, or start later in therapy. You may need a lower dose or need to stop taking the medicine for a short period or for good.

About 3 out of every 100 people who take Metformin HCl have an unpleasant metallic taste when they start taking the medicine. It lasts for a short time.

Metformin HCl rarely causes hypoglycemia (low blood sugar) by themselves. However, hypoglycemia can happen if you do not eat enough, if you drink alcohol, or if you take other medicines to lower blood sugar.

General advice about prescription medicines

If you have questions or problems, talk with your doctor or other healthcare provider. You can ask your doctor or pharmacist for the information about Metformin HCl that is written for health care professionals. Medicines are sometimes prescribed for purposes other than those listed in a patient information leaflet. Do not use Metformin HCl for a condition for which it was not prescribed. Do not share your medicine with other people.

Questions or comments?

Call 1-877-835-5472 Monday through Friday 9AM to 5PM EST.

Manufactured by:

Amneal Pharmaceuticals of NY

Hauppauge, NY 11788

Distributed by:

Amneal Pharmaceuticals

Glasgow, KY 42141

Rev. 06-2012

also known as

This drug label information is as submitted to the Food and Drug Administration (FDA) and is intended for informational purposes only. If you think you may have a medical emergency, immediately call your doctor or dial 911. You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
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