Brand names: Glucovance
Glucovance is used in the treatment of type 2 (noninsulin dependent) diabetes. Diabetes develops when the body's ability to burn sugar declines and the unused sugar builds up in the bloodstream. Ordinarily, sugar is moved out of the blood and into the body's cells by the hormone insulin. A buildup occurs when the body either fails to make enough insulin or doesn't respond to it properly.
Glucovance is a combination of 2 drugs—glyburide and metformin—that attack high blood sugar levels in several ways. The glyburide component stimulates the pancreas to produce more insulin and helps the body use it properly. The metformin component also encourages proper insulin utilization, and in addition works to decrease sugar production and absorption.
Glucovance is prescribed when diet and exercise prove insufficient to keep blood sugar levels under control. Glucovance can also be combined with other diabetes drugs such as Avandia.
Very rarely, Glucovance has been known to cause a dangerous condition called lactic acidosis, a buildup of lactic acid in the blood. Lactic acidosis is a medical emergency that requires immediate treatment in the hospital. Notify your doctor without delay if you experience any of the following symptoms:
A slow or irregular heartbeat; a cold, dizzy, or light-headed feeling; a weak, tired, or uncomfortable feeling; stomach discomfort; trouble breathing; unusual muscle pain
Glucovance is taken once or twice a day with meals.
Side effects cannot be anticipated. If any develop or change in intensity, inform your doctor as soon as possible. Only your doctor can determine if it is safe for you to continue taking Glucovance.
Glucovance 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. It should also be avoided if you need to take medicine for congestive heart failure, and you'll probably be unable to use it if you have liver disease.
If you need to have an x-ray procedure done, find out if it requires injection of a contrast agent. If so, Glucovance will have to be temporarily discontinued. (Check with your doctor for instructions; do not discontinue the drug on your own.)
If you have ever had an allergic reaction to metformin, glyburide, or diabetes medications similar to glyburide, you should not take Glucovance. It also should not be prescribed if you have acute or chronic metabolic acidosis.
Avoid excessive alcohol intake while taking Glucovance. Heavy drinking increases the danger of lactic acidosis and can also trigger an attack of low blood sugar (hypoglycemia).
Missed meals, malnutrition, general debility, liver or kidney problems, other medications, and over-exertion also increase the risk of hypoglycemia. Symptoms of a mild case include cold sweats, dizziness, shakiness, and hunger. Severe hypoglycemia can lead to seizures and coma. If you notice any of the warning signs, check with your doctor immediately.
Lactic acidosis also becomes more likely when you become dehydrated. If you experience severe vomiting, diarrhea, fever, or if your fluid intake is significantly reduced, tell your doctor.
Taking Glucovance with certain diabetes drugs, such as rosiglitazone, can increase the risk of hypoglycemia, weight gain, and liver problems. Your doctor will periodically test your liver function to guard against any problems.
Glucovance occasionally causes a mild deficiency of vitamin B12. Your doctor will check annually and may prescribe a supplement if necessary.
Some experts suspect that the glyburide component of Glucovance may lead to more heart problems than treatment with diet alone. In a long-term trial of a similar drug, researchers noted an increase in heart-related deaths (though the overall mortality rate remained unchanged). If you have a heart condition, you may want to discuss this potential risk with your doctor.
If Glucovance is taken with certain other drugs, the effects of either drug could be increased, decreased, or altered. It is especially important to check with your doctor before combining Glucovance with the following:Airway-opening drugs such as Proventil and VentolinBeta-blockers (heart and blood-pressure drugs such as atenolol and metoprolol)Birth control pillsCalcium channel blockers (heart medications) such as nifedipine and verapamilChloramphenicolCiprofloxacinEstrogensFurosemide, hydrochlorothiazide and other diureticsIsoniazidMajor tranquilizers such as chlorpromazineMAO inhibitors such as the antidepressants phenelzine and tranylcypromineNonsteroidal anti-inflammatory drugs such as ibuprofen and naproxenNiacinPhenytoinProbenecidSteroids such as prednisoneSulfa drugs such as sulfamethoxazoleThyroid medications such as levothyroxineWarfarin
Glucovance is not recommended during pregnancy. To control blood sugar during this crucial period, most doctors prefer insulin instead of Glucovance. If you are pregnant or plan to become pregnant, inform your doctor immediately.
You'll also need to avoid Glucovance while breastfeeding. If blood sugar becomes a problem, your doctor can prescribe insulin.
Your doctor will start therapy at a low dose and increase it until your blood sugar levels are under control.
For patients not previously treated with diabetes medications
The recommended starting dose is 1.25 milligrams of glyburide with 250 milligrams of metformin once or twice daily with meals. The dosage can be increased every two weeks until blood sugar levels are controlled. The maximum recommended daily dosage of Glucovance for previously untreated patients is 10 milligrams of glyburide with 2,000 milligrams of metformin.
For patients previously treated with glyburide (or a similar drug) or metformin:
The recommended starting dose of Glucovance is either 2.5 or 5 milligrams of glyburide with 500 milligrams of metformin twice daily with meals. The maximum recommended daily dosage of Glucovance for previously treated patients is 20 milligrams of glyburide with 2,000 milligrams of metformin.
Glucovance is not for use in children.
Since kidney function declines with age, it should be closely monitored in people taking Glucovance after age 65. Older patients are usually not prescribed the maximum recommended dose of Glucovance.
An overdose of Glucovance can cause an attack of hypoglycemia requiring immediate treatment. If you experience any of the symptoms listed in "Special warnings about Glyburide, Metformin," see a doctor immediately.
An excessive dose of Glucovance can also trigger lactic acidosis. If you begin to notice the warning signs listed in "Most important fact about Glyburide, Metformin," seek emergency treatment.