Howstuffworks "Metformin Overview"

Metformin is used for the treatment of the form of diabetes mellitus that most commonly appears in adulthood -- known as type 2 or non-insulin-dependent diabetes -- and that cannot be managed by exercise and dietary therapy alone.

Metformin helps to control sugar in the blood by making the body more sensitive to insulin and by reducing the amount of sugar produced by the body. Metformin can be used alone or with other antidiabetic medications (such as sulfonylureas or insulin). In this article, you will learn everything you need to know about this drug, including treatments, side effects, interactions, and warnings. We'll get started with some general information about metformin.

Brand names (manufacturers):
Glucophage (Bristol-Myers Squibb); Glucophage XR (Bristol-Myers Squibb)

Type of drug: Oral antidiabetic

Ingredient: Metformin

Dosage forms: Tablets (500 mg, 850 mg, and 1,000 mg); Tablets, extended release (500 mg)

Storage: Store metformin at room temperature in a tightly closed container. Do not refrigerate or freeze it. Discard any outdated medication.

On the next page, you will learn the proper way to take metformin.

For more information about diabetes, try the following links:

To learn more about other medications, visit our Type 2 Diabetes Medications page.
For more information on diabetes, visit the main Type 2 Diabetes page.
To find out more about treating diabetes, check out Type 2 Diabetes Treatment main page.
For additional information on biguanides, the class of drug that metformin bleongs to, read Biguanides.

This information is solely for informational purposes. IT IS NOT INTENDED TO PROVIDE MEDICAL ADVICE. Neither the Editors of Consumer Guide (R), Publications International, Ltd., the author nor publisher take responsibility for any possible consequences from any treatment, procedure, exercise, dietary modification, action or application of medication which results from reading or following the information contained in this information. The publication of this information does not constitute the practice of medicine, and this information does not replace the advice of your physician or other health care provider. Before undertaking any course of treatment, the reader must seek the advice of their physician or other health care provider.

The brand name products mentioned in this publication are trademarks or service marks of their respective companies. The mention of any product in this publication does not constitute an endorsement by the respective proprietors of Publications International, Ltd. or HowStuffWorks.com, nor does it constitute an endorsement by any of these companies that their products should be used in the manner described in this publication.

Metformin Treatment

For metformin to work correctly, it must be taken as directed by your doctor. It is best to take metformin at the same time each day to maintain good blood sugar control. It is important to avoid missing any doses of this medication.

If you do miss a dose, take it as soon as possible. However, if it is almost time for your next regular dose of metformin, do not take the missed dose at all; just return to your regular dosing schedule. Do not double the dose. Tell your doctor if you feel any side effects from missing a dose of this drug. Metformin should be taken with a meal to lessen nausea and diarrhea. Swallow the extended-release tablets whole; do not crush or chew them.

In the next section, you will find out about the possible side effects from metformin.

For more information about diabetes, try the following links:

To learn more about other medications, visit our Type 2 Diabetes Medications page.
For more information on diabetes, visit the main Type 2 Diabetes page.
To find out more about treating diabetes, check out Type 2 Diabetes Treatment main page.
For additional information on biguanides, the class of drug that metformin bleongs to, read Biguanides.

Metformin Side Effects

Metformin has some minor effects, including headache, loss of appetite, metallic taste in mouth, nausea, stomach discomfort, or gas. These side effects should lessen as your body adjusts to the drug.

Tell your doctor about any side effects that are persistent or particularly bothersome. IT IS ESPECIALLY IMPORTANT TO TELL YOUR DOCTOR about anxiousness; cold sweats; diarrhea; excessive hunger; fast, shallow breathing; headache; muscle cramps or pain; rapid pulse; shakiness; unusual sleepiness; or unusual tiredness or weakness.

On the next page, you will learn about the possible dangerous interactions between metformin and other prescription drugs.

For more information about diabetes, try the following links:

To learn more about other medications, visit our Type 2 Diabetes Medications page.
For more information on diabetes, visit the main Type 2 Diabetes page.
To find out more about treating diabetes, check out Type 2 Diabetes Treatment main page.
For additional information on biguanides, the class of drug that metformin bleongs to, read Biguanides.

Metformin Interactions

Metformin interacts with several other types of drugs:

Cimetidine, furosemide, nifedipine, amiloride, digoxin, procainamide, quinidine, ranitidine, triamterene, or trimethoprim taken concurrently with metformin may increase the blood concentration of metformin.
Alcohol and iodinated contrast material may increase the risk for some of the serious side effects of metformin.
Metformin may decrease the amount of glyburide or furosemide in the body.
The effectiveness of metformin may be reduced by oral contraceptives, cortisonelike drugs, thiazide diuretics, estrogens, isoniazid, phenothiazines, phenytoin, and thyroid hormones.
The actions of metformin may be increased by clofibrate, monoamine oxidase (MAO) inhibitors, probenecid, propranolol, rifabutin, rifampin, salicylates, and sulfonamides.

BE SURE TO TELL YOUR DOCTOR about any medications you are currently taking, especially those listed above.

In our final section, you will learn about some general concerns for taking metformin.

For more information about diabetes, try the following links:

To learn more about other medications, visit our Type 2 Diabetes Medications page.
For more information on diabetes, visit the main Type 2 Diabetes page.
To find out more about treating diabetes, check out Type 2 Diabetes Treatment main page.
For additional information on biguanides, the class of drug that metformin bleongs to, read Biguanides.

Metformin Warnings

The following are some additional precautions to observe when taking metformin:

It is important to tell your doctor if you have ever had an unusual or allergic reaction to any medication, especially to metformin.
It is also important to tell your doctor if you now have or ever had kidney disease, liver disease, or heart disease.
When taking the extended-release tablets, it is normal for the inactive part of the tablet to be eliminated in the feces as a soft mass.
Avoid drinking alcohol while taking metformin. Alcohol may increase the risk of serious side effects from metformin.
Before having surgery or any other medical or dental treatment, be sure to tell your doctor or dentist that you are taking metformin. IT IS ESPECIALLY IMPORTANT TO TELL YOUR DOCTOR that you are taking metformin if you are going to have any type of X-ray or similar medical test. Your doctor may want you to stop taking metformin a few days before such testing is scheduled.
Follow any special dietary instructions provided by your doctor. This is an important part of controlling your blood sugar levels and is necessary in order for metformin to work properly.
Test for sugar in your urine as directed by your doctor. It is a convenient way to determine whether your diabetes is being controlled by metformin.
Eat or drink something containing sugar right away if you experience any symptoms of hypoglycemia (low blood sugar), such as anxiety, chills, cold sweats, cool or pale skin, drowsiness, excessive hunger, headache, nausea, nervousness, rapid heartbeat, shakiness, or unusual tiredness or weakness. It is important for your family and friends to know the symptoms of low blood sugar. They should understand what to do if they observe any of these symptoms in you.
Although it is very uncommon, metformin may cause a condition known as lactic acidosis. The symptoms of lactic acidosis are diarrhea, severe muscle pain or cramping, shallow and fast breathing, and unusual sleepiness, tiredness, or weakness. IT IS IMPORTANT TO TELL YOUR DOCTOR IMMEDIATELY if you experience any of these symptoms.
Be sure to tell your doctor if you are pregnant or plan to become pregnant. This drug has not been studied for use during pregnancy. Your doctor may switch you to insulin while you are pregnant or trying to become pregnant. And be sure to tell your doctor if you are breast-feeding an infant. Small amounts of metformin may pass into breast milk.

Metformin comes with many concerns, true, but for diabetics in need of more than just dietarry changes, metformin can be used alone or with other antidiabetic medications (such as sulfonylureas or insulin) to help control diabetes.

For more information about diabetes, try the following links:

To learn more about other medications, visit our Type 2 Diabetes Medications page.
For more information on diabetes, visit the main Type 2 Diabetes page.
To find out more about treating diabetes, check out Type 2 Diabetes Treatment main page.
For additional information on biguanides, the class of drug that metformin bleongs to, read Biguanides.