Brand name: Metformin
Pronounced: Meth-for-min
Generic name: Metformin hydrochloride
Why is Metformin prescribed?

Metformin is an oral antidiabetic medication used to treat type 2 (non-insulin-dependent) diabetes. Diabetes develops when the body proves unable to burn sugar and the unused sugar builds up in the bloodstream. Metformin lowers the amount of sugar in your blood by decreasing sugar production and absorption and helping your body respond better to its own insulin, which promotes the burning of sugar. It does not, however, increase the body's production of insulin.

Metformin is sometimes prescribed along with insulin or certain other oral antidiabetic drugs such as Micronase or Glucotrol. It is also used alone.

Standard Metformin tablets are taken two or three times daily. An extended-release form (Metformin XR) is available for once-daily dosing.

Always remember that Metformin is an aid to, not a substitute for, good diet and exercise. Failure to follow a sound diet and exercise plan can lead to serious complications such as dangerously high or low blood sugar levels. Remember, too, that Metformin is not an oral form of insulin and cannot be used in place of insulin.

Metformin side effects

Side effects cannot be anticipated. If any develop or change in intensity, tell your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Metformin .

If side effects from Metformin occur, they usually happen during the first few weeks of therapy. Most side effects are minor and will go away after you've taken Metformin for a while.

* Side effects may include:
Abdominal discomfort, diarrhea, gas, headache, indigestion, nausea, vomiting, weakness

Why should Metformin not be prescribed?

Metformin is processed primarily by the kidneys, and can build up to excessive levels in the body if the kidneys aren't working properly. It should be avoided if you have kidney disease or your kidney function has been impaired by a condition such as shock, blood poisoning, or a heart attack.

You should not use Metformin if you need to take medicine for congestive heart failure.

Do not take Metformin if you have ever had an allergic reaction to metformin.

Do not take Metformin if you have metabolic or diabetic ketoacidosis (a life-threatening medical emergency caused by insufficient insulin and marked by excessive thirst, nausea, fatigue, pain below the breastbone, and fruity breath). Diabetic ketoacidosis should be treated with insulin.
Special warnings about Metformin

Before you start therapy with Metformin , and at least once a year thereafter, your doctor will do a complete assessment of your kidney function. If you develop kidney problems while on Metformin , your doctor will discontinue Metformin . If you are an older person, you will need to have your kidney function monitored more frequently, and your doctor may want to start you at a lower dosage.

You should not take Metformin for 2 days before and after having an X-ray procedure (such as an angiogram) that uses an injectable dye. Also, if you are going to have surgery, except minor surgery, you should stop taking Metformin . Once you have resumed normal food and fluid intake, your doctor will tell you when you can start drug therapy again.

Avoid drinking too much alcohol while taking Metformin . Heavy drinking increases the danger of lactic acidosis and can also trigger an attack of low blood sugar.

Because poor liver function could increase the risk of lactic acidosis, your doctor may decide to check your liver function before prescribing Metformin and periodically thereafter. If you develop liver problems, your doctor may stop treatment with Metformin .

If you are taking Metformin , you should check your blood or urine periodically for abnormal sugar (glucose) levels. Your doctor will do annual blood checks to see if Metformin is causing a vitamin B12 deficiency or any other blood problem.

Metformin does not usually cause hypoglycemia (low blood sugar). However, it remains a possibility, especially in older, weak, and undernourished people and those with kidney, liver, adrenal, or pituitary gland problems. The risk of low blood sugar increases when Metformin is combined with other diabetes medications. The risk is also boosted by missed meals, alcohol, and excessive exercise. To avoid low blood sugar, you should closely follow the diet and exercise plan suggested by your doctor.

If your blood sugar becomes unstable due to the stress of a fever, injury, infection, or surgery, your doctor may temporarily take you off Metformin and ask you to take insulin instead.

You should stop taking Metformin if you become seriously dehydrated, since this increases the likelihood of developing lactic acidosis. Tell your doctor if you lose a significant amount of fluid due to vomiting, diarrhea, fever, or some other condition.

The effectiveness of any oral antidiabetic, including Metformin , may decrease with time. This may occur because of either a diminished responsiveness to Metformin or a worsening of the diabetes.
Possible food and drug interactions when taking Metformin

If Metformin meds is taken with certain other drugs, the effects of either could be increased, decreased, or altered. It is especially important to check with your doctor before combining Metformin with the following:

Amiloride (Moduretic)
Calcium channel blockers (heart medications) such as Calan, Isoptin, and Procardia
Cimetidine (Tagamet)
Decongestant, airway-opening drugs such as Sudafed and Ventolin
Digoxin (Lanoxin)
Estrogens such as Premarin
Furosemide (Lasix)
Glyburide (Micronase)
Isoniazid (Rifamate), a drug used for tuberculosis
Major tranquilizers such as Thorazine
Morphine
Niacin (Niaspan)
Nifedipine (Adalat, Procardia)
Oral contraceptives
Phenytoin (Dilantin)
Procainamide (Procanbid, Pronestyl)
Quinidine (Quinidex)
Quinine
Ranitidine (Zantac)
Steroids such as prednisone (Deltasone)
Thyroid hormones such as Synthroid
Triamterene (Dyazide, Dyrenium)
Trimethoprim (Bactrim, Septra)
Vancomycin (Vancocin)
Water pills (diuretics) such as HydroDIURIL, Dyazide, and Moduretic

Do not drink too much alcohol, since excessive alcohol consumption can cause low blood sugar and alcohol enhances some effects of Metformin .
Special information if you are pregnant or breastfeeding

If you are pregnant or plan to become pregnant, tell your doctor immediately. Metformin should not be taken during pregnancy. Since studies suggest the importance of maintaining normal blood sugar (glucose) levels during pregnancy, your doctor may prescribe insulin injections instead.

It is not known whether Metformin appears in human breast milk. Therefore, women should discuss with their doctors whether to discontinue Metformin or to stop breastfeeding. If the medication is discontinued and if diet alone does not control glucose levels, then your doctor may consider insulin injections.
Recommended dosage for Metformin

Your doctor will tailor your dosage to your individual needs.

ADULTS
Overdosage

An overdose of Metformin can cause lactic acidosis (see "Most important fact about Metformin "). If you suspect a Metformin overdose, seek emergency treatment immediately.

Most important fact about Metformin

Metformin could cause a very rare--but potentially fatal--side effect known as lactic acidosis. It is caused by a buildup of lactic acid in the blood. The problem is most likely to occur in people whose liver or kidneys are not working well, and in those who have multiple medical problems, take several medications, or have congestive heart failure. The risk also is higher if you are an older adult or drink alcohol. Lactic acidosis is a medical emergency that must be treated in a hospital. Notify your doctor immediately if you experience any of the following:

* Symptoms of lactic acidosis may include:
Dizziness, extreme weakness or tiredness, light-headedness, low body temperature, rapid breathing or trouble breathing, sleepiness, slow or irregular heartbeat, unexpected or unusual stomach discomfort, unusual muscle pain

How should you take Metformin ?

Do not take more or less of Metformin than directed by your doctor. The drug should be taken with food to reduce the possibility of nausea or diarrhea, especially during the first few weeks of therapy.

If taking Metformin XR, be sure to swallow the tablet whole; do not crush it or chew it. The inactive ingredients in the tablet may occasionally appear in the stool. This is not a cause for concern.

If you miss a dose Metformin /Metformin

Take it as soon as you remember. If it is almost time for your next dose, skip the one you missed and go back to your regular schedule. Never take 2 doses at the same time.

Storage instructions Metformin

Store it at room temperature.