Brand Name(s):
  • Orinase®¶
WHY is this medicine prescribed?

Tolbutamide is used along with diet and exercise, and sometimes with other medications, 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). Tolbutamide is in a class of medications called sulfonylureas. Tolbutamide 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. Tolbutamide is 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).

Over time, people who have diabetes and high blood sugar can develop serious or life-threatening complications, including heart disease, stroke, kidney problems, nerve damage, and eye problems. Taking medication(s), making lifestyle changes (e.g., diet, exercise, quitting smoking), and regularly checking your blood sugar may help to manage your diabetes and improve your health. This therapy may also decrease your chances of having a heart attack, stroke, or other diabetes-related complications such as kidney failure, nerve damage (numb, cold legs or feet; decreased sexual ability in men and women), eye problems, including changes or loss of vision, or gum disease. Your doctor and other healthcare providers will talk to you about the best way to manage your diabetes.

HOW should this medicine be used?

Tolbutamide comes as a tablet to take by mouth. It is usually taken once a day in the morning. Tell your doctor if tolbutamide upsets your stomach. Your doctor may tell you to take smaller doses of tolbutamide more than once a day. To help you remember to take tolbutamide, take it at around the same time(s) every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take tolbutamide 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 tolbutamide and gradually increase your dose if needed. After you have taken tolbutamide for some time, tolbutamide may not control your blood sugar as well as it did at the beginning of your treatment. Your doctor may adjust the dose of your medication as needed so that the medication will work best for you. Be sure to tell your doctor how you are feeling and if your blood sugar test results have been higher or lower than normal at any time during your treatment.

Are there 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 tolbutamide,

  • tell your doctor and pharmacist if you are allergic to tolbutamide, any other medications, or any of the ingredients in tolbutamide. Ask your pharmacist for a list of the ingredients.
  • 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 anticoagulants ('blood thinners') such as warfarin (Coumadin); aspirin and other nonsteroidal anti-inflammatory medications (NSAIDs) such as ibuprofen (Advil, Motrin) and 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), nimodipine (Nimotop), nisoldipine (Sular), and verapamil (Calan, Isoptin, Verelan); chloramphenicol; diuretics ('water pills'); fluconazole (Diflucan), hormone replacement therapy and hormonal contraceptives (birth control pills, patches, rings, implants, and injections); insulin or other medications to treat high blood sugar or diabetes; isoniazid (INH); MAO inhibitors such as isocarboxazid (Marplan), phenelzine (Nardil), selegiline (Eldepryl, Emsam, Zelapar), and tranylcypromine (Parnate); medications for asthma and colds; medications for mental illness and nausea; miconazole (Monistat); niacin; oral steroids such as dexamethasone (Decadron, Dexone), methylprednisolone (Medrol), and prednisone (Deltasone); phenytoin (Dilantin); probenecid (Benemid); salicylate pain relievers such as choline magnesium trisalicylate, choline salicylate (Arthropan), diflunisal (Dolobid), magnesium salicylate (Doan's, others), and salsalate (Argesic, Disalcid, Salgesic); sulfa antibiotics such as co-trimoxazole (Bactrim, Septra); sulfasalazine (Azulfidine); and thyroid medications. Also be sure to tell your doctor or pharmacist if you stop taking any medications while taking tolbutamide. Your doctor may need to change the doses of your medications or monitor you carefully for side effects.
  • tell your doctor if you have or have ever had G6PD deficiency (an inherited condition causing premature destruction of red blood cells or hemolytic anemia); if you have hormone disorders involving the adrenal, pituitary, or thyroid gland; or if you have heart, kidney, or liver disease.
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking tolbutamide, call your doctor.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking tolbutamide.
  • 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.
  • plan to avoid unnecessary or prolonged exposure to sunlight and to wear protective clothing, sunglasses, and sunscreen. Tolbutamide may make your skin sensitive to sunlight.
  • ask your doctor what to do if you get sick, develop an infection or fever, experience unusual stress, or are injured. These conditions can affect your blood sugar and the amount of tolbutamide you may need.
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 healthy diet, exercise regularly, and lose weight if necessary.

What should I do IF I FORGET to take a dose?

Before you start to take tolbutamide, ask you doctor what you should do if you forget to take a dose. Write these directions down so that you can refer to them later.

As a general rule, take the missed dose as soon as you remember it. 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 medicine 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.

Tolbutamide may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

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

Some side effects can be serious. If you experience any of these symptoms, call your doctor immediately:

  • yellowing of the skin or eyes
  • light-colored stools
  • dark urine
  • pain in the upper right part of the stomach
  • unusual bruising or bleeding
  • diarrhea
  • fever
  • sore throat

Tolbutamide may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

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 Web Site] or by phone [1-800-332-1088].

In one study, people who took tolbutamide to treat their diabetes were more likely to die of heart problems than people who were treated with insulin and diet changes. Talk to your doctor about the risks of taking tolbutamide.

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.

What should I do in case of 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:

  • seizures
  • loss of consciousness
What OTHER INFORMATION should I know?

Keep all appointments with your doctor and the laboratory. Your blood sugar and urine sugar levels should be checked regularly to determine your response to tolbutamide. Your doctor may order other lab tests, including glycosylated hemoglobin (HbA1c), to check your response to tolbutamide. Your doctor will also tell you how to check your response to this medication by measuring your blood or urine sugar levels at home. Follow these instructions carefully.

Before having any laboratory test, tell your doctor and the laboratory personnel that you are taking tolbutamide.

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.

¶This branded product is no longer on the market. Generic alternatives may be available.

AHFS® Consumer Medication Information. © Copyright, The American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland. All Rights Reserved. Duplication for commercial use must be authorized by ASHP.

Selected Revisions: February 15, 2014.