Metformin may rarely cause a serious. life-threatening condition called lactic acidosis. Tell your doctor if you are over 80 years old and if you have ever had a heart attack; stroke; diabetic ketoacidosis (blood sugar that is high enough to cause severe symptoms and requires emergency treatment) or coma; or heart, kidney, or liver disease.
Tell your doctor if you have recently had any of the following conditions, or if you develop them during treatment: serious infection; severe diarrhea, vomiting, or fever; or if you drink much less fluid than usual for any reason. You may have to stop taking glyburide and metformin until you recover.
If you are having surgery, including dental surgery, any x-ray procedure in which dye is injected, or any major medical procedure, tell the doctor that you are taking glyburide and metformin. You may need to stop taking glyburide and metformin before the procedure and wait 48 hours to restart treatment. Your doctor will tell you exactly when you should stop taking glyburide and metformin and when you should start taking it again.
If you experience any of the following symptoms, stop taking glyburide and metformin and call your doctor immediately: extreme tiredness, weakness, or discomfort; nausea; vomiting; stomach pain; decreased appetite; deep and rapid breathing or shortness of breath; dizziness; lightheadedness; fast or slow heartbeat; flushing of the skin; muscle pain; or feeling cold.
Tell your doctor if you regularly drink alcohol or sometimes drink large amounts of alcohol in a short time (binge drinking). Drinking alcohol increases your risk of developing lactic acidosis or may cause a decrease in blood sugar. Consuming alcohol while taking glyburide and metformin also rarely may cause symptoms such as flushing (reddening of the face), headache, nausea, vomiting, chest pain, weakness, blurred vision, mental confusion, sweating, choking, breathing difficulty, and anxiety. Ask your doctor how much alcohol is safe to drink while you are taking glyburide and metformin.
Keep all appointments with your doctor and the laboratory. Your doctor will order certain tests to check your body's response to glyburide and metformin. Talk to your doctor about the risks of taking glyburide and metformin.
Why is this medication prescribed?
The combination of glyburide and metformin is used to treat type 2 diabetes (condition in which the body does not use insulin normally and therefore cannot control the amount of sugar in the blood) in people whose diabetes cannot be controlled by diet and exercise alone. Glyburide belongs to a class of drugs called sulfonylureas, and metformin is in a class of drugs called biguanides. Glyburide lowers blood sugar by causing the pancreas to produce insulin (a natural substance that is needed to break down sugar in the body) and helping the body use insulin efficiently. This medication will only help lower blood sugar in people whose bodies produce insulin naturally. Metformin helps your body control the amount of glucose (sugar) in your blood. It decreases the amount of glucose you absorb from your food and the amount of glucose made by your liver. It also helps your body use its own insulin more effectively. Glyburide and metformin are not used to treat type 1 diabetes (condition in which the body does not produce insulin and therefore cannot control the amount of sugar in the blood) or diabetic ketoacidosis (a serious condition that may occur if high blood sugar is not treated).
How should this medicine be used?
Glyburide and metformin combination comes as a tablet to take by mouth. It is usually taken one to two times daily with meals. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take glyburide and metformin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Your doctor will probably start you on a low dose of glyburide and metformin and may gradually increase your dose, not more than once every 2 weeks. depending on your response. Monitor your blood glucose closely.
Glyburide and metformin combination controls diabetes but does not cure it. Continue to take glyburide and metformin even if you feel well. Do not stop taking glyburide and metformin without talking to your doctor.
Ask your pharmacist or doctor for a copy of the manufacturer's information for the patient.
Other uses for this medicine
This medication is sometimes prescribed for other uses; ask your doctor or pharmacist for more information.
What special precautions should I follow?
Before taking glyburide and metformin,
- tell your doctor and pharmacist if you are allergic to glyburide, metformin, any of the ingredients in glyburide and metformin tablets, or any other medications. Ask your pharmacist for a list of the ingredients.
- tell your doctor if you are taking bosentan (Tracleer). Your doctor may tell you not to take glyburide if you are taking this medication.
- tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: acetazolamide (Diamox); amiloride (Midamor, in Moduretic); angiotensin-converting enzyme (ACE) inhibitors such as benazepril (Lotensin), captopril (Capoten), enalapril (Vasotec), fosinopril (Monopril), lisinopril (Prinivil, Zestril), moexipril (Univasc), perindopril (Aceon), quinapril (Accupril), ramipril (Altace), and trandolapril (Mavik); anticoagulants ('blood thinners') such as warfarin (Coumadin); aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen (Advil, Motrin) or naproxen (Aleve, Naprosyn); beta-blockers such as atenolol (Tenormin), labetalol (Normodyne), metoprolol (Lopressor, Toprol XL), nadolol (Corgard), and propranolol (Inderal); calcium channel blockers such as amlodipine (Norvasc), diltiazem (Cardizem, Dilacor, Tiazac, others), felodipine (Plendil), isradipine (DynaCirc), nicardipine (Cardene), nifedipine (Adalat, Procardia), or verapamil (Calan, Isoptin, Verelan); chloramphenicol; cimetidine (Tagamet); clarithromycin (Biaxin); cyclosporine (Neoral, Sandimmune); digoxin (Lanoxin); disopyramide (Norpace); diuretics ('water pills'); fluconazole (Diflucan); fluoxetine (Prozac, Sarafem); furosemide (Lasix); hormone replacement therapy; insulin or other medications for diabetes; isoniazid; MAO inhibitors such as isocarboxazid (Marplan), phenelzine (Nardil), selegiline (Eldepryl, Emsam, Zelaplar), and tranylcypromine (Parnate); medications for allergies, asthma, and colds; medications for mental illness and nausea; ; miconazole (Lotrimin, Monistat, others); morphine (MS Contin, others); niacin; oral contraceptives (birth control pills); oral steroids such as dexamethasone (Decadron, Dexone), methylprednisolone (Medrol), and prednisone (Deltasone); phenytoin (Dilantin Phenytek); probenecid (Benemid, in Colbenemid); procainamide (Procanbid); quinidine; quinine; quinolone and fluoroquinolone antibiotics such as cinoxacin (Cinobac), ciprofloxacin (Cipro), enoxacin (Penetrex), gatifloxacin (Tequin), levofloxacin (Levaquin), lomefloxacin (Maxaquin), moxifloxacin (Avelox), nalidixic acid (NegGram), norfloxacin (Noroxin), ofloxacin (Floxin), sparfloxacin (Zagam), trovafloxacin and alatrofloxacin combination (Trovan); ranitidine (Zantac); rifampin; salicylate pain relievers such as choline magnesium trisalicylate, choline salicylate (Arthropan), diflunisal (Dolobid), magnesium salicylate (Doan's, others), or salsalate (Argesic, Disalcid, Salgesic); sulfa antibiotics such as cotrimoxazole (Bactrim, Septra); sulfasalazine (Azulfidine); thyroid medications; topiramate (Topamax); triamterene (in Dyazide, Maxzide, others); trimethoprim (Primsol); vancomycin (Vancocin, others); or zonisamide (Zonegran).
- in addition to the conditions listed in the IMPORTANT WARNING section, tell your doctor if you or any of your family members have or have ever had G6PD deficiency (an inherited condition causing premature destruction of red blood cells or hemolytic anemia); also tell your doctor if you have or have ever had hormone disorders involving the adrenal, pituitary, or thyroid gland or; acute or chronic metabolic acidosis.
- tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking glyburide and metformin, call your doctor.
- plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. Glyburide and metformin may make your skin sensitive to sunlight.
- tell your doctor if you eat less or exercise more than usual. This can affect your blood sugar. Your doctor will give you instructions if this happens.
What special dietary instructions should I follow?
Be sure to follow all exercise and dietary recommendations made by your doctor or dietitian. It is important to eat a healthful diet.
What should I do if I forget a dose?
Before you start taking glyburide and metformin, ask your doctor what to do if you forget to take a dose or accidentally take an extra dose. Write these directions down so you can refer to them later.
As a general rule, take the missed dose as soon as you remember it. However, if it is almost time for the next dose, skip the missed dose and continue your regular dosing schedule. Do not take a double dose to make up for a missed one.
What side effects can this medication cause?
This medication may cause changes in your blood sugar. You should know the symptoms of low and high blood sugar and what to do if you have these symptoms.
Glyburide and metformin may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:
- stomach pain
- nausea or vomiting
If you experience any of the following symptoms or those listed in the IMPORTANT WARNING section, call your doctor immediately:
- chest pain
- yellowing of the skin or eyes
- light-colored stools
- dark urine
- pain in the right upper part of the stomach
- unusual bleeding or bruising
- sore throat
- swelling of the eyes, face, lips, tongue, or throat
In one study, people who took a medication similar to glyburide to treat their diabetes were more likely to die of heart problems than people who were treated with insulin and diet changes.
Some female laboratory animals given high doses of metformin developed non-cancerous polyps (abnormal growths of tissue) in the uterus (womb). It is not known if metformin increases the risk of polyps in humans.
If you experience a serious side effect, you or your doctor may send a report to the Food and Drug Administration's (FDA) MedWatch Adverse Event Reporting program online [at http://www.fda.gov/Safety/MedWatch] or by phone [1-800-332-1088].
What should I know about storage and disposal of this medication?
Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from light, excess heat, and moisture (not in the bathroom). Throw away any medication that is outdated or no longer needed. Talk to your pharmacist about the proper disposal of your medication.
In case of emergency/overdose
In case of overdose, call your local poison control center at 1-800-222-1222. If the victim has collapsed or is not breathing, call local emergency services at 911.
Symptoms of overdose may include hypoglycemia symptoms as well as the following:
- loss of consciousness
- extreme tiredness
- stomach pain
- decreased appetite
- deep, rapid breathing
- shortness of breath
- abnormally fast or slow heartbeat
- flushing of the skin
- muscle pain
- feeling cold
What other information should I know?
Your doctor will tell you how to check your response to glyburide and metformin by measuring your blood sugar levels at home. Follow these instructions carefully.
You should always wear a diabetic identification bracelet to be sure you get proper treatment in an emergency.
Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.
It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.
Brand names of combination products
- Glucovance® (containing Glyburide, Metformin)