Sounds like 'gli-cla-zide'

Key points about gliclazide

  • Gliclazide is used to treat type 2 diabetes.
  • It belongs to a group of medicines called sulfonylureas.
  • Gliclazide is commonly called Glizide.
  • Find out how to take it safely and possible side effects.
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Gliclazide is used to treat type 2 diabetes. It works by increasing the amount of insulin produced by your pancreas and in this way lowers high blood glucose. Gliclazide can be used alone or with other medicines (such as metformin), along with good nutrition and regular exercise. It is one of a group of medicines known as sulfonylureas. In New Zealand, gliclazide is available as tablets (80 mg). 

Read more about type 2 diabetes and medicines for type 2 diabetes

  • The dose of gliclazide will be different for different people.
  • Your doctor will start you on a low dose and increase your dose gradually, depending on your blood glucose level. This allows your body to get used to the medicine and reduces unwanted side effects.
  • The usual dose is from one half (40 mg) to four tablets (320 mg) each day. 
  • Each day's tablets are usually given once a day (breakfast) or divided into two doses (breakfast and dinner),
  • Always take your gliclazide exactly as your doctor has told you. The pharmacy label on your medicine will tell you how much gliclazide to take, how often to take it, and any special instructions.


My dose is:

Date Breakfast Dinner

  • Timing: Gliclazide may be given once or two times a day. Your doctor will tell you how often to take it. If prescribed once each day, take your dose in the morning with breakfast. Take gliclazide at about the same times each day so that this becomes part of your daily routine, which will help you to remember. 
    If taken two times a day, take your doses in the morning and in the evening, with your meal. 
    Do not skip meals while taking gliclazide – this can increase your risk of hypoglycaemia.
  • Limit alcohol while you are taking gliclazide. It may increase your risk of side effects.
  • Missed dose: If you forget to take your dose, take it (with food) as soon as you remember. But, if it is nearly time for your next dose, just take the next dose at the right time. Do not take double the dose.
  • Keep taking gliclazide regularly. To control your diabetes you must take gliclazide everyday. Speak to your doctor or nurse before stopping. Contact your doctor or nurse for advice if you have been unwell and missed meals.
  • If you are unwell: If you are not eating well regardless of the type of illness, stop taking gliclazide – you are at increased risk of low blood glucose (hypoglycaemia). Restart when you are well (usually after 24–48 hours of eating and drinking normally). Ask your healthcare provider for advice. Read more about diabetes sick day plan

Note: there is also a similar-sounding medicine called glipizide. This is also used to treat type 2 diabetes. If your tablets look different to your last supply, ask your doctor or pharmacist for advice.

  • Do you have problems with your kidneys or liver?
  • Are you pregnant or breastfeeding?
  • Are you overweight?
  • Have ever had an allergic reaction to a medicine? 

If so, it’s important that you tell your doctor or pharmacist before you start gliclazide. Sometimes a medicine isn’t suitable for a person with certain conditions, or it can only be used with extra care.

Like all medicines, gliclazide can cause side effects, although not everyone gets them. Often side effects improve as your body gets used to the new medicine.


Low blood glucose

Sometimes gliclazide may lower your blood glucose too much. This is called hypoglycaemia or a 'hypo'.

  • Hypos are most likely to occur when gliclazide is used together with metformin or insulin to control your diabetes, if you have kidney problems (chronic kidney disease) or are elderly or have taken gliclazide but missed a meal.
  • Hypoglycaemia may cause you to feel weak, faint, dizzy, drowsy or irritable. You may get a headache, tremor (shakes) or blurred vision.
  • If this occurs, drink something sweet such as a small glass of sweetened soft drink, or fruit juice or eat something sweet such as lollies or glucose tablets. Follow this up with a snack such as a sandwich.
  • Tell your doctor or nurse if this happens.
  • Read more about low blood glucose and diabetes sick day plan.


Other side effects

Side effects What should I do?
  • Feeling sick (nausea) or vomiting
  • Diarrhoea (runny poos)
  • Constipation
  • These are quite common when you first start taking gliclazide and usually go away with time.
  • Tell your doctor if troublesome. 
  • Weight gain
  • Gliclazide can cause some people to gain weight.
  • Lifestyle changes can be helpful in preventing weight gain, such as making better eating choices, limiting your portion sizes, and getting more exercise. Read more about medicines and weight gain.
  • Tell your doctor if you are concerned.
  • Signs of problems with your liver such as yellow skin and eyes, dark urine and stomach pain
  • Tell your doctor immediately or ring HealthLine on 0800 611 116
  • Signs of an allergic reaction such as skin rashes, itching, redness or swelling of the face, lips, mouth or have problems breathing.
  • Tell your doctor immediately or ring HealthLine on 0800 611 116
Did you know that you can report a side effect to a medicine to CARM (Centre for Adverse Reactions Monitoring)? Report a side effect to a product(external link)

Gliclazide can interact with some medicines and herbal supplements so check with your doctor or pharmacist before starting gliclazide or before starting any new medicines.

The following links have more information on gliclazide.

Gliclazide(external link) (te reo Māori(external link)) New Zealand Formulary Patient Information
Glizide (Gliclazide)(external link) Medsafe Consumer Information Sheet


  1. Gliclazide(external link) New Zealand Formulary 
  2. Managing patients with type 2 diabetes: from lifestyle to insulin(external link) BPAC Dec 2015

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Credits: Sandra Ponen, Pharmacist, Healthify He Puna Waiora. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Angela Lambie, Pharmacist, Auckland

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