Gliclazide: Uses, Dosage, Side Effects & Precautions

Gliclazide is a sulfonylurea tablet used to control blood sugar in adults with type 2 diabetes, along with diet, exercise and weight management. This guide covers gliclazide uses, how it works, dosage, side effects, precautions, drug interactions, use in pregnancy and breastfeeding and its approximate price in India.

What is Gliclazide?

Gliclazide is a second-generation sulfonylurea used to treat type 2 diabetes. It helps control blood sugar levels by stimulating insulin secretion from the pancreas.

How Gliclazide Works

Gliclazide stimulates the beta cells in the pancreas to release more insulin, helping to lower blood glucose levels, especially after meals. It works only when the pancreas can still make insulin, which is why it is not used in type 1 diabetes.

Uses of Gliclazide

• Type 2 diabetes: Used in adults when diet, exercise and weight loss alone are not enough to control blood sugar.
• Blood sugar after meals: It increases insulin release in response to meals, which helps reduce high blood glucose after eating.
• Combination treatment: Doctors may combine gliclazide with other diabetes medicines such as metformin, or with insulin, under close medical supervision.

Gliclazide Dosage and How to Take It

Gliclazide dosing depends on the formulation and the specific product. Do not assume that a dose for one product applies to another. For example, 80 mg immediate-release and 60 mg modified-release tablets are different products with different dosing, and a doctor must decide any switch with blood sugar monitoring.

Immediate-release tablets (UK Servier information for Diamicron 80 mg)

• The total daily dose may range from 40 to 320 mg, adjusted to your blood sugar response.
• Treatment usually starts at 40–80 mg daily and is increased until control is adequate.
• A single dose should not exceed 160 mg. When higher total doses are needed, they are taken in two doses with the main meals of the day.

Modified-release (MR) tablets (UK/EU Servier information for Diamicron MR)

• Taken once daily at breakfast.
• The usual starting dose is 30 mg daily. If blood sugar is not controlled, the doctor may increase the dose in steps (60, 90, then 120 mg). The steps are usually at least a month apart, unless blood sugar has not fallen after two weeks.
• The maximum recommended dose is 120 mg daily.
• Swallow the tablet whole. Do not crush or chew it. Some MR tablets are scored and can be halved, while others cannot, so follow your product leaflet and break a tablet only if your doctor tells you to.

Other brands and Indian package inserts may differ. Always follow the insert in your pack and your doctor’s instructions.

Meals

Take gliclazide with food as directed (breakfast for MR tablets), and always eat a meal afterward. You should eat regularly. Skipped or delayed meals, or low-carbohydrate meals, increase the risk of low blood sugar.

Kidney and liver problems (UK/EU Servier information)

• Mild to moderate kidney impairment: The usual dosing may be used with careful monitoring.
• Severe kidney or liver impairment: Gliclazide is contraindicated, and insulin is recommended. Your doctor decides any change in treatment.

Older adults

The same dosing regimen as for adults under 65 is used, but the risk of low blood sugar may be higher and warning symptoms less obvious. Your doctor decides the dose.

Higher risk of low blood sugar

(for example if undernourished, or with severe or poorly controlled hormone disorders): The lowest recommended starting dose is advised.

Missed dose

Do not take a double dose. Take the next dose at the usual time, and ask your doctor or pharmacist if you are unsure.

Children

Not recommended for children and adolescents under 18, because safety and efficacy have not been established.

Take this medicine only as advised by your doctor or healthcare professional. Do not start, stop, or change the dose on your own.

Side Effects of Gliclazide

Most common:

• Hypoglycemia (low blood sugar)

Other effects reported:

• Nausea, vomiting, abdominal pain, indigestion, diarrhea, or constipation. UK product information says these can be avoided or minimized if gliclazide is taken with breakfast or a meal.
• Temporary blurred vision, especially at the start of treatment, due to changes in blood sugar
• Skin reactions such as rash, itching, or hives
• Weight gain, which can occur with sulfonylurea medicines. Ask your doctor about diet and activity.

Hypoglycemia (low blood sugar)

• Signs can include hunger, sweating, shakiness, palpitations, headache, dizziness, anxiety, poor concentration, confusion, and drowsiness.
• Low blood sugar is more likely if you skip or delay meals, drink alcohol, exercise strenuously without enough food, take too high a dose, or take other glucose-lowering medicines.
• Symptoms may be less obvious in older adults and in people taking beta-blockers.
• Mild episodes usually improve after taking sugar or glucose, according to the plan your doctor has given you. Sugar-free artificial sweeteners will not correct low blood sugar.
• Symptoms can return after the first improvement, so tell your doctor about any episode.
• Severe or prolonged low blood sugar is an emergency and needs immediate medical attention, even if sugar temporarily helps.
• Low blood sugar can reduce alertness and reaction time. Be careful when driving or using machinery, especially when starting treatment.

Seek medical help promptly for

• Severe, repeated, or prolonged low blood sugar
• Swelling of the face, lips, tongue or throat, difficulty breathing, or a widespread rash with blistering or peeling skin. Serious reactions such as Stevens-Johnson syndrome, toxic epidermal necrolysis, and DRESS have been rarely reported.
• Yellowing of the skin or eyes (jaundice), which may point to liver problems
• Unusual paleness, bruising or bleeding, sore throat, or fever, which may reflect changes in blood cell counts

Who Should Not Take Gliclazide, and Precautions

Do not use gliclazide if you

• Are allergic to gliclazide, other sulfonylureas, sulfonamides, or any ingredient in the tablet
• Have type 1 diabetes, diabetic ketoacidosis, or diabetic pre-coma or coma
• Have severe kidney or liver impairment
• Are taking miconazole (see Drug Interactions)
• Are breastfeeding (see Pregnancy and Breastfeeding)

Use only under medical supervision if you

• Do not eat regularly: Gliclazide should be prescribed only if you are likely to have regular meals, including breakfast.
• Have G6PD deficiency: Sulfonylureas can cause hemolytic anemia (breakdown of red blood cells) in susceptible patients, and your doctor may consider a non-sulfonylurea alternative.
• Are under stress, such as injury, surgery, fever or infection: Blood sugar control may worsen and temporary insulin may be needed.

Your doctor will usually monitor your blood sugar and HbA1c. The effect of oral diabetes medicines can weaken over time in some people.

Gliclazide Drug Interactions

Tell your doctor or pharmacist about all prescription medicines, over-the-counter medicines, supplements and herbal products you use. This list is not complete and comes from Servier product information.

• Miconazole (oral or oromucosal gel): Must not be combined with gliclazide, because it can cause severe low blood sugar, even coma.
• Alcohol: Increases the risk of low blood sugar and should be avoided, including medicines that contain alcohol.
• Phenylbutazone (systemic): Product information advises against combining it with gliclazide.
• Danazol: Not recommended, because it can raise blood sugar.
• Other diabetes medicines, including insulin: Can increase the risk of low blood sugar.
• Other medicines that can increase low blood sugar risk: Beta-blockers (which can also mask warning signs), fluconazole, ACE inhibitors, H2 blockers, MAO inhibitors, sulfonamide antibiotics, clarithromycin, and NSAIDs.
• Medicines that can raise blood sugar: Systemic and some local corticosteroids, high-dose chlorpromazine, intravenous salbutamol, ritodrine or terbutaline, and St John’s wort.
• Fluoroquinolone antibiotics: Can cause both low and high blood sugar, especially in older adults, so careful monitoring is advised.
• Warfarin-type blood thinners: Sulfonylureas may increase the anticoagulant effect, and the doctor may adjust the dose.

Gliclazide in Pregnancy and Breastfeeding

Product information differs by country:

• UK/European Servier information: It is preferable to avoid gliclazide during pregnancy, as data are limited. Insulin is the first-choice treatment, and a switch from tablets to insulin is recommended before a planned pregnancy or as soon as pregnancy is discovered.
• Canada and Australia: Gliclazide is contraindicated in pregnancy.
• Breastfeeding: Gliclazide is contraindicated in breastfeeding mothers in all of these sources, because of the risk of low blood sugar in the newborn.

I could not review an Indian package insert for gliclazide, so check the insert for your specific brand. If you are pregnant, planning pregnancy, or become pregnant, or if you are breastfeeding, contact your doctor promptly. Do not stop treatment on your own, as poorly controlled blood sugar can also harm both mother and baby.

Gliclazide Brands, Strengths and Approximate Price in India

Diamicron is also marketed as MR 30 mg and as XR presentations, and Reclide in 40 mg, MR and XR forms. Some brands combine gliclazide with metformin, such as Glycinorm-M and Diamicron XR Mex. These contain two medicines and have different dosing instructions, so they must not be swapped with plain gliclazide.

Prices are approximate and may vary by brand, strength, pack size, pharmacy, location, availability and discounts. Prices are MRPs from Indian pharmacy listings checked in October 2026, and some listings showed products as out of stock.

How HealthPil Can Help

Medicines should be started, adjusted, or stopped only under the guidance of a qualified healthcare professional. If you have questions about this medicine, its side effects, or your treatment plan, you can consult a doctor through HealthPil. HealthPil connects you to diabetes specialists for better management.