Medically reviewed by Drugs.com. Last updated on Oct 17, 2021.
Commonly used brand name(s)
In the U.S.
Available Dosage Forms:
Therapeutic Class: Hypoglycemic
Chemical Class: 1st Generation Sulfonylurea
Uses for tolbutamide
Tolbutamide is used to treat high blood sugar levels caused by a type of diabetes mellitus (sugar diabetes) called type 2 diabetes. In type 2 diabetes, your body does not work properly to store excess sugar and the sugar remains in your bloodstream. Chronic high blood sugar can lead to serious health problems in the future.
Proper diet is the first step in managing type 2 diabetes, but often medicines are needed to help your body. Tolbutamide belongs to a class of drugs called sulfonylureas. It causes your pancreas to release more insulin into the blood stream.
Tolbutamide is available only with your doctor's prescription.
Before using tolbutamide
In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For tolbutamide, the following should be considered:
Tell your doctor if you have ever had any unusual or allergic reaction to tolbutamide or any other medicines. Also tell your health care professional if you have any other types of allergies, such as to foods, dyes, preservatives, or animals. For non-prescription products, read the label or package ingredients carefully.
Appropriate studies have not been performed on the relationship of age to the effects of tolbutamide in the pediatric population. Safety and efficacy have not been established.
No information is available on the relationship of age to the effects of tolbutamide in geriatric patients. However, elderly patients are more likely to have age-related heart, liver, or kidney problems which may require an adjustment of dosage in patients receiving tolbutamide.
There are no adequate studies in women for determining infant risk when using this medication during breastfeeding. Weigh the potential benefits against the potential risks before taking this medication while breastfeeding.
Interactions with medicines
Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking tolbutamide, it is especially important that your healthcare professional know if you are taking any of the medicines listed below. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using tolbutamide with any of the following medicines is usually not recommended, but may be required in some cases. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Thioctic Acid
Using tolbutamide with any of the following medicines may cause an increased risk of certain side effects, but using both drugs may be the best treatment for you. If both medicines are prescribed together, your doctor may change the dose or how often you use one or both of the medicines.
- Aminolevulinic Acid
- Bitter Melon
- Ginkgo Biloba
- Guar Gum
- Methylene Blue
Interactions with food/tobacco/alcohol
Certain medicines should not be used at or around the time of eating food or eating certain types of food since interactions may occur. Using alcohol or tobacco with certain medicines may also cause interactions to occur. The following interactions have been selected on the basis of their potential significance and are not necessarily all-inclusive.
Using tolbutamide with any of the following is usually not recommended, but may be unavoidable in some cases. If used together, your doctor may change the dose or how often you use tolbutamide, or give you special instructions about the use of food, alcohol, or tobacco.
Other medical problems
The presence of other medical problems may affect the use of tolbutamide. Make sure you tell your doctor if you have any other medical problems, especially:
- Alcohol intoxication or
- Underactive adrenal glands or
- Underactive pituitary glands or
- Undernourished condition or
- Weakened physical condition or
- Any other condition that causes low blood sugar—Patients with these conditions may be more likely to develop low blood sugar while taking tolbutamide.
- Diabetic ketoacidosis (ketones in the blood) or
- Type I diabetes—Should not be used in patients with these conditions.
- Fever or
- Infection or
- Surgery or
- Trauma—These conditions may cause temporary problems with blood sugar control and your doctor may want to treat you temporarily with insulin.
- Heart disease—Use with caution. May make this condition worse.
- Kidney disorder or
- Liver disorder—Higher blood levels of tolbutamide may occur, which may cause serious problems.
Proper use of tolbutamide
Follow carefully the special meal plan your doctor gave you. This is the most important part of controlling your condition, and is necessary if the medicine is to work properly. Also, exercise regularly and test for sugar in your blood or urine as directed.
The dose of tolbutamide will be different for different patients. Follow your doctor's orders or the directions on the label. The following information includes only the average doses of tolbutamide. If your dose is different, do not change it unless your doctor tells you to do so.
The amount of medicine that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are using the medicine.
- For type 2 diabetes:
- For oral dosage form (tablets):
- Adults—At first, 1000 to 2000 milligrams (mg) per day, taken in the morning or in divided doses. Your doctor may adjust your dose if needed. The dose is usually not more than 3000 mg per day.
- Children—Use and dose must be determined by your doctor.
- For oral dosage form (tablets):
Precautions while using tolbutamide
It is very important that your doctor check your progress at regular visits to make sure that tolbutamide is working properly. Blood tests may be needed to check for unwanted effects.
It is very important to follow carefully any instructions from your health care team about:
- Alcohol—Drinking alcohol may cause severe low blood sugar. Discuss this with your health care team.
- Counseling—Other family members need to learn how to prevent side effects or help with side effects if they occur. Also, patients with diabetes may need special counseling about diabetes medicine dosing changes that might occur because of lifestyle changes, such as changes in exercise and diet. Furthermore, counseling on contraception and pregnancy may be needed because of the problems that can occur in patients with diabetes during pregnancy.
- Travel—Keep your recent prescription and your medical history with you. Be prepared for an emergency as you would normally. Make allowances for changing time zones and keep your meal times as close as possible to your usual meal times.
- In case of emergency—There may be a time when you need emergency help for a problem caused by your diabetes. You need to be prepared for these emergencies. It is a good idea to wear a medical identification (ID) bracelet or neck chain at all times. Also, carry an ID card in your wallet or purse that says you have diabetes and a list of all of your medicines.
Check with your doctor right away if you start having chest pain or discomfort; nausea; pain or discomfort in arms, jaw, back, or neck; shortness of breath; sweating; or vomiting while you are using tolbutamide. These may be symptoms of a serious heart problem, including a heart attack.
Tolbutamide can cause low blood sugar. However, this can also occur if you delay or miss a meal or snack, drink alcohol, exercise more than usual, cannot eat because of nausea or vomiting, take certain medicines, or take tolbutamide with another type of diabetes medicine. The symptoms of low blood sugar must be treated before they lead to unconsciousness (passing out). Different people feel different symptoms of low blood sugar. It is important that you learn which symptoms of low blood sugar you usually have so you can treat it quickly.
Symptoms of low blood sugar include anxiety; behavior change similar to being drunk; blurred vision; cold sweats; confusion; cool, pale skin; difficulty in thinking; drowsiness; excessive hunger; fast heartbeat; headache (continuing); nausea; nervousness; nightmares; restless sleep; shakiness; slurred speech; or unusual tiredness or weakness.
If symptoms of low blood sugar occur, eat glucose tablets or gel, corn syrup, honey, or sugar cubes; or drink fruit juice, non-diet soft drink, or sugar dissolved in water. Also, check your blood for low blood sugar. Glucagon is used in emergency situations when severe symptoms such as seizures (convulsions) or unconsciousness occur. Have a glucagon kit available, along with a syringe or needle, and know how to use it. Members of your household also should know how to use it.
Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.
Tolbutamide side effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
- Abdominal or stomach pain
- clay-colored stools
- dark urine
- loss of appetite
- unpleasant breath odor
- unusual tiredness or weakness
- vomiting of blood
Incidence not known
- back or leg pains
- bleeding gums
- blood in urine or stools
- bloody, black, or tarry stools
- chest pain
- cough or hoarseness
- decreased urine output
- difficulty breathing
- fast or irregular heartbeat
- fever with or without chills
- fluid-filled skin blisters
- general body swelling
- general feeling of tiredness or weakness
- high fever
- increased thirst
- light-colored stools
- lower back or side pain
- muscle pain or cramps
- muscle twitching
- painful or difficult urination
- pale skin
- pinpoint red spots on skin
- rapid weight gain
- sensitivity to the sun
- shortness of breath
- sore throat
- sores, ulcers, or white spots on the lips or in the mouth
- swelling of face, ankles, or hands
- swollen or painful glands
- tightness in the chest
- unexplained bleeding or bruising
- yellow eyes or skin
Get emergency help immediately if any of the following symptoms of overdose occur:
Symptoms of overdose
- blurred vision
- cold sweats
- cool, pale skin
- increased hunger
- slurred speech
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
- pain in the chest below the breastbone
- passing of gas
- stomach pain, fullness, or discomfort
- Flushing or redness of skin
- unusually warm skin
Incidence not known
- Change in taste or bad, unusual, or unpleasant (after)taste
- increased sensitivity of skin to sunlight
- redness or other discoloration of skin
- severe sunburn
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.
More about tolbutamide
- Side effects
- Drug interactions
- Dosage information
- During pregnancy or Breastfeeding
- Drug images
- Drug class: sulfonylureas
- Other brands
Related treatment guides
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