Tolbutamide
Peer reviewed by Sid DajaniLast updated by Michael Stewart, MRPharmSLast updated 7 Nov 2022
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Take tolbutamide tablets with food.
Remember to follow any advice you have been given about what you should or shouldn't eat, and try to take some regular exercise.
Side-effects are rare, but make sure you know how to recognise the symptoms of low blood sugar (glucose). These include feeling shaky or anxious, sweating, looking pale, feeling hungry, having a feeling that your heart is pounding (palpitations), and feeling dizzy.
In this article:
Continue reading below
About tolbutamide
Type of medicine | A sulfonylurea antidiabetic medicine |
Used for | Type 2 diabetes mellitus |
Available as | Tablets |
Insulin is a hormone which is made naturally in your body, in the pancreas. It helps to control the levels of sugar (glucose) in your blood. If your body does not make enough insulin to meet its needs, or if it does not use the insulin it makes effectively, this results in the condition called diabetes (diabetes mellitus).
People with diabetes need treatment to control the amount of sugar in their blood. This is because good control of blood sugar levels reduces the risk of complications later on. Some people can control the sugar in their blood by making changes to the food they eat but for other people, medicines like tolbutamide are given alongside the changes in diet.
Tolbutamide works by increasing the amount of insulin that your pancreas produces. It can be given on its own or alongside other antidiabetic medicines or insulin.
Before taking tolbutamide
Some medicines are not suitable for people with certain conditions, and sometimes a medicine can only be used if extra care is taken. For these reasons, before you start taking tolbutamide it is important that your doctor knows:
If you are pregnant or breastfeeding.
If you have any problems with the way your liver works, or if you have any problems with the way your kidneys work.
If you have been told you have either porphyria or glucose-6-phosphate dehydrogenase (G6PD) deficiency. These are both rare inherited disorders.
If you are taking any other medicines. This includes any medicines which are available to buy without a prescription, as well as herbal and complementary medicines.
If you have ever had an allergic reaction to a medicine.
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How to take tolbutamide
Before you start the treatment, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about tolbutamide, and it will also provide you with a full list of the side-effects which you could experience from taking it.
Take tolbutamide exactly as your doctor tells you to. It is usually prescribed as a once-daily dose of 1-3 tablets (500 mg strength) with breakfast, although some people are asked to take the tablets in divided doses over the day. Your doctor or pharmacist will tell you which is right for you, and this information will also be printed on the label of the pack of tablets to remind you about what the doctor said.
If you are asked to take tolbutamide as a once-daily dose, take the tablets during your breakfast or immediately afterwards. If you are asked to take several doses of tolbutamide during a day, then take each of the doses during a mealtime or immediately afterwards. Swallow the tablets with a drink of water.
If you forget to take a dose, take it at the next mealtime. Try to take the correct number of tablets each day, but do not take two doses together to make up for a missed dose.
Getting the most from your treatment
It is important that you keep your regular doctor's and clinic appointments. This is so your progress can be monitored. You are likely to need regular check-ups with an eye clinic and a foot clinic as well as with your doctor and diabetes clinic.
Your doctor may recommend that you test for sugar (glucose) in your blood regularly to check that your diabetes is being controlled. Your doctor or diabetes nurse will show you how to do this.
If you have been given advice by your doctor about changes to your diet, stopping smoking or taking regular exercise, it is important for you to follow the advice you have been given.
Make sure you know what it feels like if your blood sugar is too low. This is known as hypoglycaemia, or a 'hypo'. The first signs of hypoglycaemia are feeling shaky or anxious, sweating, looking pale, feeling hungry, having a feeling that your heart is pounding (palpitations), and feeling dizzy. If this happens, eat something containing sugar, such as dextrose tablets, or sugary sweets or drinks (non-diet), and then follow this up with a snack such as a sandwich or a banana.
Hypoglycaemia can occur in particular if you miss a meal, if you exercise more than usual, if you are ill, or if you drink a lot of alcohol.
If you are a driver you should take special care, as your ability to concentrate may be affected if your diabetes is not well controlled. You may be advised to check your blood sugar levels before you travel and to have a snack with you on long journeys.
Drivers in the UK may need to inform the Driver and Vehicle Licensing Agency (DVLA) if they experience an episode of severe hypoglycaemia or experience a 'hypo' whilst driving. Ask your doctor for advice. Drivers in other countries should contact the relevant vehicle licensing agency.
Check with your doctor before taking up any new physical exercise, as this will have an effect on your blood sugar levels and you may need to check your blood levels more regularly.
Drinking alcohol is not advisable with tolbutamide. If you do have a drink, keep well within the recommended alcohol limits, as alcohol will affect the control of your blood sugar.
If you get unusually thirsty, pass urine more frequently, and feel very tired then let your doctor know. Your dose of tolbutamide may need adjusting.
If you are due to have an operation or dental treatment, you should tell the person carrying out the treatment that you have diabetes and that you are taking tolbutamide.
If you buy any medicines, check with a pharmacist that they are suitable for you to take. This is because some medicines may interfere with tolbutamide.
Treatment for diabetes is lifelong. Continue to take the tablets unless you are advised otherwise by your doctor.
Continue reading below
Can tolbutamide cause problems?
Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the ones associated with tolbutamide. The best place to find a full list of the side-effects which can be associated with your medicine is from the manufacturer's printed information leaflet supplied with the medicine. Alternatively, you can find an example of a manufacturer's information leaflet in the reference section below. Speak with your doctor or pharmacist if any of the following continue or become troublesome.
Tolbutamide side-effects - these occur only rarely | What can I do if I experience this? |
Headache | Drink plenty of water and ask your pharmacist to recommend a suitable painkiller. If the headaches continue, let your doctor know |
Increased appetite and weight, stomach upset (sickness, constipation or diarrhoea), ringing in the ear (tinnitus) | If troublesome, speak with your doctor |
Signs of low blood sugar : feeling shaky or anxious, sweating, looking pale, feeling hungry, feeling that your heart is pounding (palpitations), feeling dizzy | Eat something containing sugar, such as a biscuit or a sugary drink (not diet), and follow this up with a snack such as a sandwich. Tell your doctor if you notice these symptoms, as your dose may need adjusting |
If you experience any other symptoms which you think may be due to the tablets, speak with your doctor or pharmacist for further advice.
How to store tolbutamide
Keep all medicines out of the reach and sight of children.
Store in a cool, dry place, away from direct heat and light.
Important information about all medicines
Important information about all medicines
Never take more than the prescribed dose. If you suspect that you or someone else might have taken an overdose of this medicine, go to the accident and emergency department of your local hospital at once. Take the container with you, even if it is empty.
This medicine is for you. Never give it to other people even if their condition appears to be the same as yours.
Do not keep out-of-date or unwanted medicines. Take them to your local pharmacy which will dispose of them for you.
If you have any questions about this medicine ask your pharmacist.
Report side effects to a medicine or vaccine
If you experience side effects, you can report them online through the Yellow Card website.
Further reading and references
- Manufacturer's PIL, Tolbutamide 500 mg Tablets; Waymade Plc, Sovereign Medical. Dated January 2017.
- Medicines Complete BNF 88th Edition; British Medical Association and Royal Pharmaceutical Society of Great Britain, London.
Article history
The information on this page is written and peer reviewed by qualified clinicians.
Next review due: 6 Nov 2025
7 Nov 2022 | Latest version
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