An older first-generation sulfonylurea for type 2 diabetes
Tolazamide
An older first-generation sulfonylurea once used for type 2 diabetes, now largely obsolete.
What is Tolazamide?
Tolazamide is an older medicine for type 2 diabetes, belonging to a group called sulfonylureas, which lower blood sugar by helping the pancreas release more insulin. It is a first-generation sulfonylurea, an early member of the group, and is now largely obsolete, with newer sulfonylureas and other diabetes medicines used in its place. Like other sulfonylureas, it can cause low blood sugar (hypoglycaemia) and weight gain. It is taken by mouth and is included here mainly for historical and reference purposes.
Education and reference only. This is a plain-language guide to Tolazamide — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Tolazamide is a medicine that was used to treat type 2 diabetes, the form of diabetes where the body does not use insulin well enough. It belongs to a group called sulfonylureas, which lower blood sugar by prompting the pancreas to release more insulin. Tolazamide is a first-generation sulfonylurea, one of the earlier medicines in this group. It is now largely obsolete, having been replaced by newer sulfonylureas and other diabetes treatments, so it is described here mainly for historical and educational reference rather than as a current first choice.
How it works
Tolazamide works by encouraging the pancreas to release more insulin, the hormone that moves sugar from the blood into the body's cells for energy. By boosting insulin, it lowers blood sugar levels. Because it makes the body release more insulin regardless of the current blood sugar, it can sometimes push blood sugar too low, which is why low blood sugar (hypoglycaemia) is a recognised risk with sulfonylureas. It is taken by mouth and works over the course of the day, but as an older medicine it has largely been superseded by newer options.
Company & origin
Originated / developed by: Historical / generic.
An older first-generation sulfonylurea once used for type 2 diabetes, now largely obsolete and rarely used.
What it treats
Conditions Tolazamide is used for
Practical use
How to take Tolazamide
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it by mouth as prescribed, usually with food, and eat regular meals to reduce the risk of low blood sugar.
- Learn to recognise and treat low blood sugar (shakiness, sweating, hunger, confusion) and keep a fast-acting sugar to hand.
- Be careful with alcohol, which can make low blood sugar more likely.
- Do not skip meals after taking it, as this raises the risk of a low.
- Ask your diabetes team whether a newer medicine would suit you better, as this is an older option.
Weighing it up
Advantages & disadvantages of Tolazamide
Advantages
- Lowers blood sugar in type 2 diabetes by helping the pancreas release more insulin.
- Taken by mouth as a tablet.
- A long-established medicine, though now largely replaced by newer options.
Disadvantages
- Can cause low blood sugar (hypoglycaemia), sometimes severe.
- Can cause weight gain.
- An older, first-generation sulfonylurea that is now largely obsolete.
Practical use
Good to know
The main thing to know is that tolazamide is an older, largely obsolete sulfonylurea, and most people with type 2 diabetes today are treated with newer medicines that have advantages in safety or convenience. Like other sulfonylureas, its two best-known drawbacks are that it can cause low blood sugar (hypoglycaemia), with symptoms such as shakiness, sweating, hunger and confusion, and that it can lead to weight gain. Because of the hypoglycaemia risk, it is important to know how to recognise and treat a low, to eat regularly, and to be careful with alcohol. Anyone currently managing type 2 diabetes should discuss with their team which medicines are recommended now, as the choices have moved on considerably from first-generation sulfonylureas.
Who should not take it / use with caution
- People who have had a serious allergic reaction to tolazamide or other sulfonylureas should not take it.
- It is not used for type 1 diabetes or for diabetic emergencies such as ketoacidosis.
- It is used with caution, or avoided, in people with significant kidney or liver problems and in older people at higher risk of lows.
Monitoring
- Checking blood sugar control and watching for episodes of low blood sugar.
- Reviewing weight over time.
- Reviewing kidney and liver function and whether a newer medicine would be more suitable.
Side effects
- Low blood sugar (hypoglycaemia), with shakiness, sweating, hunger or confusion.
- Weight gain.
- Stomach upset, and less commonly skin reactions or changes in blood tests.
Key interactions
- Alcohol and some other medicines can increase the risk of low blood sugar.
- Other diabetes medicines add to the blood-sugar-lowering effect and the risk of lows.
- Some medicines can mask the warning signs of a low, so tell your prescriber about all your medicines.
Available as: Tablets taken by mouth.
Answers
Tolazamide: frequently asked questions
What is tolazamide used for?
It is an older sulfonylurea medicine used to treat type 2 diabetes, lowering blood sugar by helping the pancreas release more insulin.
Why is it called obsolete?
It is a first-generation sulfonylurea that has largely been replaced by newer sulfonylureas and other diabetes medicines with advantages in safety or convenience.
Can it cause low blood sugar?
Yes. Like other sulfonylureas it can cause low blood sugar (hypoglycaemia), so it is important to recognise and treat lows and to eat regularly.
Does it cause weight gain?
Weight gain is a recognised effect of sulfonylureas, including tolazamide, which is one reason newer medicines are often preferred.
Should I switch to a newer medicine?
Ask your diabetes team; treatment choices have moved on considerably from first-generation sulfonylureas, and a newer medicine may suit you better.
The wider class
About Sulfonylurea (older, first-generation)
Tolazamide belongs to the sulfonylurea (older, first-generation) class. For how the class as a whole works, its shared safety principles and monitoring, see the full guide.
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Authoritative sources
- BNF
- NICE CKS
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