Gliclazide: Uses, Side Effects, Mechanism of Action, Precautions, Interactions and Contraindications

It is an oral antidiabetic; it is used to lower sugar in the blood.

It is used only in patients diagnosed with type II diabetes.

It can be used in conjunction with insulin or other medications to achieve better control over blood sugar levels. A controlled diet and exercise routine can give better results.


Gliclazide is used for the treatment, control, prevention, and improvement of the following diseases, conditions, and symptoms:

  • Treatment of type 2 diabetes mellitus.
  • Maturity-onset diabetes.
  • Polycystic ovary syndrome.

Gliclazide can also be used for purposes not mentioned here.

Side effects of gliclazide

See your doctor if you notice any of the following side effects, especially if they don’t go away:

  • Nausea.
  • Gastrointestinal disorders.
  • Low PH in tissues and blood of the body.
  • Lack or loss of appetite.
  • Vomiting
  • Diarrhea.
  • Weightloss.
  • Flatulence.
  • The altered sense of taste includes the metallic taste.
  • Eruption.

Gliclazide can also cause side effects not mentioned here.


If you notice other side effects not listed above, contact your doctor for medical advice. You can also report side effects to your local food and drug management authority.

Mechanism of action and pharmacology

Gliclazide improves the patient’s condition by performing the following functions:

  • It lowers the amount of glucose and controls the amount of glucose in the blood.
  • The amount of insulin released by the pancreas is increased.

Gliclazide precautions and how to use

The recommended dose of gliclazide ranges from 80 mg to 320 mg daily. 160 mg or more should be taken in two equally divided doses. Gliclazide should be taken with food if possible. The daily dose should not exceed 320 mg.

Essential points of advice are listed below:

  1. Blurry vision.
  2. Diabetic cetoacidosis.
  3. Stop using this medicine if jaundice or hepatitis occurs.
  4. If you also take a blood thinner, your blood thinner dose may need to be adjusted.
  5. Patients with liver failure.
  6. Patients with kidney failure.
  7. Risk of hypoglycemia in case of overdose.
  8. Risk of hypoglycemia when the consumption of calories or glucose is deficient.
  9. Symptoms include nausea, vomiting, abdominal pain, fatigue, anorexia, and dark urine.

Who should not take this medicine?

Do not take this medicine if:

  • You are allergic to gliclazide or any ingredient in the medication.
  • You are allergic to other sulfonylureas (such as glyburide) or sulfonamides (such as sulfamethoxazole).
  • You are pregnant or breastfeeding.
  • You are taking some forms of miconazole (ask your doctor or pharmacist for more information).
  • You are undergoing surgery or have suffered recent severe trauma.
  • You have a severe infection.
  • You have severely reduced kidney or liver function.
  • You have type 1 diabetes.
  • You have unstable diabetes or ketoacidosis (high ketones in the urine).

Gliclazide interactions with other medications

If you take other medications or over-the-counter products simultaneously, the effects of gliclazide may change. This can increase your risk of side effects or make your medicine not work correctly.

Tell your doctor about all medications, vitamins, and herbal supplements you are using, so your doctor can help you prevent or manage drug interactions. Gliclazide may interact with the following drugs and products:

  • Alcohol.
  • Antidiabetic drugs.
  • Antidiabetic agents.
  • Beta-Blockers.
  • Captopril.
  • Chlorpromazine.
  • Clarithromycin .
  • Danazol.
  • Enalapril.
  • Fluconazole
  • Amiodarone
  • Aprepitant.
  • Angiotensin receptor blockers (ARBs, eg candasartan, irbesartan, losartan).
  • Aripiprazole.
  • ‘Azolic’ antimycotic drugs (eg fluconazole , miconazole, voriconazole).
  • Barbiturates (p. Ej., Phenobarbital, thiopental).
  • Betabloqueantes (p. ej., metoprolol, propranolol).
  • Bosentan.
  • Buserelin.
  • Capecitabine.
  • Carbamazepine.
  • Inhaled corticosteroids (eg, budesonide, ciclesonide, fluticasone).
  • Oral corticosteroids (e.g., dexamethasone, hydrocortisone, prednisone).
  • Antidepresivos cíclicos (p. ej., amitriptilina, clomipramina, desipramina, trimipramina).
  • Cyclosporine .
  • Dabrafenib.

If you are taking any of these medications, talk to your doctor or pharmacist.


Hypersensitivity to gliclazide is a contraindication. Also, gliclazide should not be used if you have the following conditions:

  • Acute myocardial infarction.
  • Diabetic cetoacidosis.
  • Diabetic precoma and coma.
  • Hypersensitivity to sulfonamides.
  • Lactation.
  • Renal disease.

Important information about gliclazide

Gliclazide overdose

Do not use more than the prescribed dose. Taking more medicine will not improve your symptoms; instead, it can cause poisoning or serious side effects.

If you suspect that you or anyone else has overdosed on gliclazide, go to the nearest hospital or nursing home emergency department. Take a kit, container, or label to help doctors with the necessary information.

Do not give your medicines to other people, even if you know they have the same condition or it seems they may have similar requirements. This can lead to an overdose.

Consult your doctor or pharmacist, or product package for more information.

Gliclazide storage

Store medicines at room temperature, away from heat and direct light. Do not freeze medications unless required by the package insert. Keep medicines away from children and pets.

Do not flush medications down the toilet or pour them down the drain unless instructed. Medication discarded in this way can pollute the environment. Please consult your pharmacist or doctor for more details on safely disposing of gliclazide.

Gliclazide expired

A single expired dose of gliclazide is unlikely to produce an adverse event. However, talk to your primary healthcare provider or pharmacist for proper advice or if you feel unwell or ill.

Expired medication may become ineffective in treating your prescribed conditions. To be safe, it is essential not to use expired medications.

Suppose you have a chronic illness that requires constant medication, such as life-threatening heart conditions, seizures, and allergies. In that case, it is much safer to contact your primary healthcare provider so that you can have a fresh supply of unexpired medications.

Common questions

How does gliclazide work specifically?

Gliclazide is a type of medicine known as sulfonylurea. Sulfonylureas increase the amount of insulin made by the pancreas. Insulin is the hormone that controls the level of sugar in the blood.

When will I feel better?

You may not have had any symptoms of diabetes, so you won’t necessarily feel different when taking gliclazide. This does not mean that gliclazide is not working, and it is essential to keep taking it.

Gliclazide will help keep your blood sugar level stable and reduce your chances of future diabetes-related problems.

How long will I take gliclazide?

Diabetes treatment is usually life-long. Do not stop taking your gliclazide tablets without consulting your doctor.

Can I take gliclazide for a long time?

Gliclazide is safe to take for a long time. There is no evidence that it harms your pancreas or your general health.

However, gliclazide may stop working correctly after a while. Your doctor may want to stop it or add a different medicine to help keep your blood sugar stable.

What will happen if I suddenly stop taking gliclazide?

Do not stop taking gliclazide without consulting your doctor.

If you stop taking gliclazide suddenly, your diabetes may get worse.

Am I going to gain weight?

Gliclazide can make you hungrier and retain water, so it can be challenging to avoid gaining weight while taking it. Try to eat a healthy, balanced diet without increasing your portion sizes, so you don’t gain too much weight. Regular exercise will also help keep your weight stable.

Are other diabetes medications better?

There are other groups of drugs that can lower blood sugar levels:

  • Metformin.
  • Pioglitazone.
  • DPP-4 inhibitors such as saxagliptin.
  • SGLT2 inhibitors such as dapagliflozin.
  • GLP-1 agonists as exenatide.
  • Insulin.

Gliclazide can be prescribed alone or in combination with the above medications.

It is usually prescribed if you cannot take metformin or if metformin no longer keeps your blood sugar under control when used alone.

Gliclazide is a sulfonylurea. There are four other sulfonylureas available:

  • Glibenclamide.
  • Glimepiride.
  • Glipizide.
  • Tolbutamide.

All of these work in the same way by increasing the amount of insulin your body produces.

Can I take pain relievers with gliclazide?

It is safe to take acetaminophen with gliclazide.

Don’t take aspirin or ibuprofen – These pain relievers can interfere with gliclazide and lower your blood sugar levels too much.

Can I drive or ride a bike?

If your blood sugar levels are stable, your ability to drive, use bicycles, or use machines or tools should not be affected by gliclazide.

However, if your blood sugar levels drop too low, this can lower its concentration. Don’t drive, cycle, or use machines or tools until you feel better if this happens to you.

Do not drive or use machines or tools if you begin to feel symptoms of low blood sugar.

Will it affect my fertility?

Gliclazide does not affect male or female fertility.

Will it affect my contraception?

Gliclazide does not interfere with any contraception.

Some women may need to adjust their dose of gliclazide if they start taking the contraceptive pill. This is because birth control pills can occasionally raise blood sugar levels.

Can I drink alcohol with the medicine?

Yes, you can drink alcohol while taking gliclazide, but men and women should consume no more than two units per day. They are drinking more than this can increase the risk of hypoglycemia.

Usually, a standard wine glass or beer can is two units.

Are there any foods or drinks that I should avoid?

It is a good idea to cut down on foods with added sugar. Check nutrition labels as many foods and drinks are high in sugar, such as:

  • Sweet.
  • Cakes
  • Cookies.
  • Chocolate.
  • Some fizzy drinks.
  • Juices
  • Karela (also called bitter gourd) is used to flavor foods such as curries and bitter gourd masala. It has a bitter taste and is also made into juice and tea.

Be careful eating foods and drinks that contain karela, as they can lower blood sugar levels, and your diabetes is not controlled as well as it should.

Can I take gliclazide before having surgery?

If you have an operation, tell your doctor that you are taking gliclazide.

This is because gliclazide increases the risk of hypoglycemia during the operation. Low blood sugar can be challenging to detect when using a general anesthetic (which puts you to sleep).

For a few days, around the time of the operation, your doctor may temporarily switch you to insulin.

Can lifestyle changes help my diabetes?

You can make some lifestyle changes to help manage your diabetes symptoms.

These include:

  • Eating a healthy diet.
  • Lose any excess weight
  • No Smoking.
  • Do not drink too much alcohol; specifically, no more than two units per day is recommended.
  • Exercising regularly, up to 30 minutes a day, five times a week, is ideal.