Gliclazide

What is gliclazide?

Gliclazide is a prescription only medicine primarily used to treat type 2 diabetes. It belongs to a group of medicines called sulfonylureas – these help lower blood sugar levels by increasing the amount of insulin produced by the pancreas[1]. 

What is gliclazide used for?

Gliclazide is licensed to treat type 2 diabetes mellitus in adults. It helps to reduce high blood sugar levels when diet, exercise and weight loss alone are not enough to control them, reducing the impact of type 2 diabetes[1]. 

How does gliclazide work?

Gliclazide works primarily by stimulating the pancreas to produce more insulin. This helps to lower blood glucose levels and maintain better blood sugar control when patients are unable to do so naturally[1]. 

Who can take gliclazide?

Gliclazide can be taken by adults aged 18 and over who have type 2 diabetes. However, it may not be suitable for people who have: 

• Had an allergic reaction to gliclazide 

• Insulin dependent type 1 diabetes  

• Diabetic ketoacidosis (ketones and sugar in urine) 

• Severe liver or kidney problems 

• Acute porphyria (a genetic disorder) 

It is not usually recommended if you are pregnant or breastfeeding, unless advised by a specialist[1]. 

Please tell your doctor or pharmacist about any conditions you may have before you start treatment and always follow the instructions in the Patient Information Leaflet[2]. 

How do you take gliclazide?

Gliclazide tablets are usually best swallowed whole with water and taken at the same time each day before a meal. You’ll usually take it with breakfast – or with both breakfast and dinner if you’ve been prescribed a twice daily dose. Slow-release tablets must not be crushed or chewed. Always follow the dosage on the label or as prescribed by your doctor or pharmacist[2]. 

What is the typical dosage of gliclazide?

Gliclazide is available as standard-release and modified-release (MR) tablets. The exact dosage will depend on your blood sugar levels and how you respond to treatment. In most cases, it’s usually taken once or twice a day with food to reduce the risk of low blood sugar. Your doctor may adjust your dose gradually based on your needs to get the best possible usage[1]. 

Can you stop taking gliclazide suddenly?

You should not stop taking gliclazide without speaking to healthcare professional first. Stopping suddenly may cause your blood sugar levels to rise too high, which can be dangerous and bring serious side effects. If you need to stop due to side effects or other concerns, your doctor will advise you on how to do so safely and in a controlled manner[1]. 

What should you do if you take too much gliclazide?

Taking too much gliclazide can cause hypoglycaemia, or low blood sugar. The symptoms of this may include: 

• Excess sweating 

• Intense hunger  

• Nausea and vomiting 

• Dizziness 

• Confusion  

• Shaking 

If you experience the symptoms of low blood sugar you should eat or drink something sugary straight away, such as glucose tablets or fruit juice. If your symptoms are severe or do not improve, call 999 or go to A&E immediately[1]. 

What should you do if you forget a dose of gliclazide?

If you forget to take a dose of gliclazide, take it as soon as you remember. Alternatively, if it’s nearly time for your next dose, skip the missed one and take the next dose as usual. Do not take two doses at the same time. You should also monitor your blood sugar and speak to your healthcare provider if you forget doses regularly. Taking your gliclazide at the same time each day can help you remember to take them regularly[1]. 

What medicines should you avoid while taking gliclazide?

Gliclazide can interact with certain medicines, and you should inform your doctor or pharmacist if you are taking any of the following[1]: 

• Other diabetes medicines used to treat high blood sugar 

• Steroids such as prednisolone 

• Some antibiotics such as clarithromycin or ciprofloxacin 

• Blood pressure medicines including beta-blockers  

• Some antidepressants  

• Antifungal medicines 

• Painkillers such ibuprofen  

• Asthma medication such as salbutamol 

• Warfarin (gliclazide may increase the blood thinning effect of warfarin) 

Always inform your doctor or pharmacist about all medications and supplements you take before you start a new medicine, and follow the instructions in the Patient Information Leaflet[2]. 

What are the side effects of gliclazide?

Some of the most common side effects of gliclazide include: 

• Low blood sugar (hypoglycaemia) - see symptoms in overdose section. Low blood sugar may also happen if you are fasting or skipping meals, if you exercise more than usual without eating sufficient carbohydrates, if you drink alcohol, or if you have thyroid, kidney, or liver problems.  

• Weight gain 

• Nausea or indigestion 

• Diarrhoea  

 Rare but serious side effects of gliclazide include[1]: 

• Liver problems, such as yellowing of the skin or eyes 

• Blood disorders, such as unusual bleeding or bruising 

• Allergic reactions, including rash and swelling 

You should contact your GP if you experience any of these symptoms. In rare cases, the medicine may cause a serious allergic reaction (anaphylaxis). You should call 999 or visit A&E immediately if you believe this is happening[1]. 

If you experience any side effects, including those not listed, you are encouraged to report them via the Yellow Card Scheme or contact your doctor, pharmacist, or nurse. This information is intended as a summary for general awareness and does not replace professional medical advice. 

The information provided in the side effects section is not a comprehensive list of all possible side effects associated with this medication. For a complete list of side effects, please refer to the Patient Information Leaflet (PIL) provided with your medication or consult your healthcare professional[2]. 

Frequently asked questions about gliclazide

Can I drink alcohol while taking gliclazide? 

You may drink alcohol while taking gliclazide – but it’s important to do so in moderation and to not exceed the recommended guideline of 14 units per week. Alcohol can increase the risk of low blood sugar, so always be cautious and monitor your blood sugar levels[1]. 

Will I gain weight while taking gliclazide? 

Some people may gain weight while taking gliclazide, particularly if they eat more to prevent low blood sugar. Maintaining a balanced diet and exercising can help manage this[1]. 

Can I drive while taking gliclazide? 

Yes, if your blood sugar levels are stable. Low blood sugar can affect your concentration and your ability to drive safely. If this happens do not drive, cycle, or operate machinery until you are feeling better.Having a sugary snack with you could be beneficial in the eventuality of low blood sugar. 

Is gliclazide safe to take long-term? 

Yes, gliclazide is generally safe to take long-term when used as prescribed and monitored regularly by your healthcare team. Your doctor may change your dose if needed[1]. 

Can I take gliclazide with metformin? 

Gliclazide is sometimes alongside metformin to help improve blood sugar control in people with type 2 diabetes. This is usually done safely and without any serious side effects. However, you should always follow your doctor’s advice and prescription and report any side effects[1]. 

For the official NHS guide to gliclazide, visit their website.