Diabetes Medications and New Drugs

Gliclazide and Glipizide

Gliclazide and Glipizide have been in common use for control of diabetes and are known to be safe and effective.

Why do I need tablets?

Type 2 Diabetes is best managed by diet, exercise and where appropriate, weight loss. However, diet alone is often insufficient to control blood sugar levels. Commonly, diet alone will control diabetes for some time but the natural progression of the condition makes tablets necessary later on.

What do these drugs do?

Gliclazide and Glipizide belong to a class of drugs known as sulphonylureas. These tablets work by stimulating the pancreas gland to produce more insulin hormone, which lowers your blood glucose. They are frequently used in combination with Metformin or other tablets to control your diabetes.

What is the dose?

Gliclazide is also known as DiamicronR and is available as 80 mg tablets which are scored and can be halved in order to take a 40 mg dose. The usual starting dose is 40 –80 mg daily. Doses higher than 160 mg should be divided. The maximum daily dose is 320 mg.

Glipizide is also known as GlibeneseR or MinodiabR. Two strengths are available; a 2.5 mg and 5 mg. The starting dose is usually 2.5 – 5 mg daily, adjusted according to response. Up to 15 mg may be taken as a single dose before breakfast, higher doses divided.

How often do I need to take these tablets?

Glipizide and Gliclazide are usually started in low dose taken about 20 minutes before breakfast. Higher doses are taken twice daily, before breakfast and before your evening meal.

Are there any side effects?

Side effects of sulphonylureas are generally mild and infrequent and sometimes cause nausea or headache. Older drugs in this class were known to cause facial flushing after alcohol, but this does not occur with the newer agents.

Sulphonylureas unfortunately have a tendency to promote weight gain. This can often be prevented by diet and exercise. They may occasionally cause hypoglycaemia (low blood sugar level). This is most likely to occur during the late morning if you have been physically active or if lunch is late. Symptoms would be faintness, sweating and disorientation. Eating a snack such as a couple of plain biscuits  will quickly make you feel better. It is important to be aware of this side effect when driving.

How long should I take this medication for?

It is important to be aware that diabetes treatment is lifelong and once you commence on tablets, you are likely to require some form of treatment for your diabetes always. Do not stop your tablets without prior discussion with your doctor. The natural course of type 2 diabetes unfortunately results in a slow loss of the ability of the pancreatic beta cells (insulin producing cells) to make insulin. A gradual loss of ‘efficacy’ is therefore usual with these tablets and many people require a progressive increase in the dose. Once the maximum dose has been reached your doctor may consider the addition of other tablets or a change to insulin therapy.


Author: Dr Robert Bradley
West Suffolk Diabetes Service
October 2002


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