Tolbutamide

Tolbutamide is a used to treat type 2 diabetes. Tolbutamide belongs to a group of drugs called sulfonylureas, which help to lower blood sugar by causing the pancreas to produce insulin (a natural substance that is needed to break down sugar in the body). It also helps the body use insulin efficiently.

This medication comes in tablet form and is taken once a day in the morning with breakfast or the first meal of the day.

The total daily dose may be taken either in the morning or in divided doses through the day.

Common side effects include nausea, feeling full, and heartburn. Tolbutamide can also cause dizziness. Do not drive or operate heavy machinery until you know how it affects you.

Tolbutamide is a prescription medication used to treat type 2 diabetes.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.

The dose your doctor recommends may be based on the following:

• other medical conditions you have
• other medications you are taking
• how you respond to this medication
• your age
• your kidney function
• your liver function

The recommended maintenance dose range of tolbutamide is 0.25 to 3 grams daily. (Maintenance doses above 2 grams are seldom required)

Serious side effects have been reported with tolbutamide including the following:

• Tolbutamide may increase your chance of death from heart problems.
• Tolbutamide can cause low blood sugar levels (hypoglycemia) in patients. Tell your doctor if you have a history of kidney or liver disease or drink alcohol. Symptoms of low blood sugar include:
  • shakiness
  • tremors
  • cold sweat
  • fast heart rate
  • headache
  • moodiness
  • dizziness
  • blurred vision
  • confusion

• Tolbutamide can decrease the number of red blood cells in people with glucose-6-phosphate dehydrogenase (G6PD) deficiency.  Alert your doctor if you have a history of G6PD deficiency or anemia.

Ask your doctor about the safe use of alcoholic beverages while you are taking tolbutamide. Alcohol can make the side effects from tolbutamide worse. Consuming alcohol while taking tolbutamide also 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.

Avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. Tolbutamide may make your skin sensitive to sunlight.

After exposure to stress, such as fever, trauma, infection, or surgery, tolbutamide may cause you to lose control over your blood glucose levels. These conditions can affect your blood sugar and the amount of tolbutamide you may need. Ask your doctor what to do in any of these cases.

Do not take tolbutamide if you:

• are allergic to tolbutamide or to any of its ingredients
• have Diabetic ketoacidosis, with or without coma. This condition should be treated with insulin.
• are being treated for Type I diabetes (as sole therapy)

Common side effects include:

• nausea
• upper abdominal fullness
• heartburn
• rash
• headache
• changes in taste

This is not a complete list of tolbutamide side effects. Ask your doctor or pharmacist for more information.

Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.

Tell your doctor about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

• nonsteroidal anti-inflammatory medications (NSAIDs) such as ibuprofen (Advil, Motrin) and naproxen (Aleve, Naprosyn)
• salicylate pain relievers
• sulfa antibiotics such as sulfamethoxazole/ trimethoprim (Bactrim, Septra)
• sulfasalazine (Azulfidine)
• probenecid (Benemid)
• chloramphenicol
• MAO inhibitors such as isocarboxazid (Marplan), phenelzine (Nardil), selegiline (Eldepryl, Emsam, Zelapar), and tranylcypromine (Parnate)
• 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), nimodipine (Nimotop), nisoldipine (Sular), and verapamil (Calan, Isoptin, Verelan)
• anticoagulants ('blood thinners') such as warfarin (Coumadin)
• aspirin
• thyroid medications
• hormonal contraceptives (birth control pills, patches, rings, implants, and injections)
• insulin or other medications to treat high blood sugar or diabetes
• isoniazid (INH)
• niacin
• oral steroids such as dexamethasone (Decadron, Dexone), methylprednisolone (Medrol), and prednisone (Deltasone)
• phenytoin (Dilantin)
• diuretics ('water pills')

This is not a complete list of tolbutamide drug interactions. Ask your doctor or pharmacist for more information.

Tell your doctor if you are pregnant or plan to become pregnant.

The FDA categorizes medications based on safety for use during pregnancy. Five categories - A, B, C, D, and X, are used to classify the possible risks to an unborn baby when a medication is taken during pregnancy.

Tolbutamide falls into category C. In animal studies, pregnant animals were given this medication and had some babies born with problems. No well-controlled studies have been done in humans. Therefore, this medication may be used if the potential benefits to the mother outweigh the potential risks to the unborn child.

Tell your doctor if you are breastfeeding or plan to breastfeed.

Although it is not known whether tolbutamide is excreted in human milk, some sulfonylurea drugs are known to be excreted in human milk. Because of the possibility for serious adverse reactions in nursing infants with use of this medication, a choice should be made whether to stop nursing or stop the use of this medication. Your doctor and you will decide if the benefits outweigh the risk of using tolbutamide.

If the drug is discontinued, and if diet alone is inadequate for controlling blood glucose, insulin therapy should be considered.

Avoid unnecessary or prolonged exposure to sunlight, and wear protective clothing, sunglasses, and sunscreen. Tolbutamide may make your skin sensitive to sunlight.

Tolbutamide can cause low blood sugar levels (hypoglycemia) in patients. Make sure you know the signs and symptoms of low blood sugar.

Tolbutamide should be taken with a healthy diet to maximize its blood glucose lowering effects.

Ask your doctor about the safe use of alcoholic beverages while you are taking tolbutamide. Alcohol can make the side effects from tolbutamide worse.