How to use Diagen
Contents of the leaflet
- Leaflet accompanying the packaging: patient information
- What is Diagen and what is it used for
- Important information before taking Diagen
- How to take Diagen
- Possible side effects
- How to store Diagen
- Contents of the packaging and other information
Leaflet accompanying the packaging: patient information
Diagen 60 mg, tablets with modified release
Gliclazide
Read the leaflet carefully before taking the medicine, as it contains important information for the patient.
- Keep this leaflet, so you can read it again if you need to.
- If you have any doubts, consult your doctor or pharmacist.
- This medicine has been prescribed specifically for you. Do not pass it on to others. The medicine may harm another person, even if their symptoms are the same.
- If the patient experiences any side effects, including those not listed in this leaflet, they should tell their doctor or pharmacist. See section 4.
Table of contents of the leaflet
- 1. What is Diagen and what is it used for
- 2. Important information before taking Diagen
- 3. How to take Diagen
- 4. Possible side effects
- 5. How to store Diagen
- 6. Contents of the packaging and other information
1. What is Diagen and what is it used for
The active substance of Diagen is gliclazide.
Diagen is a medicine that lowers blood sugar levels (it is an oral antidiabetic medicine belonging to the sulfonylurea group).
Diagen is used to treat a certain type of diabetes (type 2 diabetes) in adults, when
following a diet, exercising, and losing weight is not enough to maintain proper blood sugar levels.
2. Important information before taking Diagen
When not to take Diagen:
- if the patient is allergic to gliclazide or any of the other ingredients of this medicine (listed in section 6)
- if the patient is allergic to other medicines from the same group (sulfonylurea derivatives, such as glipizide) or other derivatives (sulfonamides, such as hydrochlorothiazide)
- if the patient has insulin-dependent diabetes (type 1)
- if ketone bodies and sugar are present in the urine (this may indicate that the patient has ketoacidosis), pre-coma or diabetic coma states
- if the patient has severe kidney or liver disease
- if the patient is taking miconazole for the treatment of fungal infections (see section "Diagen and other medicines")
- if the patient is breastfeeding (see section "Pregnancy and breastfeeding")
Warnings and precautions
Before starting to take Diagen, discuss it with your doctor or pharmacist.
This medicine should be taken only in the case of regular food intake (including breakfast). It is essential to regularly consume carbohydrates due to the increased risk of low blood sugar (hypoglycemia) in case of delayed or missed meals, inadequate meal intake, or when the meal is low in carbohydrates.
It is necessary to follow the treatment plan prescribed by the doctor to achieve proper blood sugar levels.
This means that, in addition to taking the tablets regularly, the patient should follow a diet, be physically active, and, if necessary, lose weight.
During treatment with gliclazide, regular blood sugar (and possibly urine) tests and glycated hemoglobin (HbA1c) tests are necessary.
The risk of low blood sugar (hypoglycemia) may be increased during the first weeks of treatment. Therefore, close medical supervision, including self-monitoring of blood glucose, is particularly necessary if necessary.
Low blood sugar (hypoglycemia) may occur if:
- the patient takes meals irregularly or misses meals
- the patient fasts
- the patient is undernourished
- the patient changes their diet
- the patient increases physical activity, and carbohydrate intake is not sufficient;
- the patient consumes alcohol, especially when missing meals
- the patient takes other medicines or natural products at the same time (see section "Diagen and other medicines")
- the patient takes too high a dose of gliclazide
- the patient has specific hormonal disorders (thyroid, pituitary, or adrenal disorders)
- kidney or liver function is severely impaired
- the patient has severe heart or circulatory problems (affecting blood circulation, such as angina pectoris)
If the patient has low blood sugar (hypoglycemia), the following symptoms may occur:
- headache
- strong hunger
- feeling of nausea (nausea)
- vomiting
- fatigue
- sleep disturbances
- anxiety
- aggression
- impaired concentration
- reduced alertness and reaction time
- depression
- confusion
- speech or vision disorders, which may include difficulties in reading or writing
- tremors
- sensory disturbances
- muscle weakness, partial paralysis
- dizziness
- feeling of lack of strength
The following symptoms may also occur:
- sweating
- moist skin
- anxiety
- rapid or irregular heartbeat
- high blood pressure
- sudden, severe chest pain that may radiate to adjacent areas (angina pectoris)
If the following symptoms occur, contact a doctor or the nearest hospital:
If blood sugar levels continue to decrease, significant confusion (stupor), convulsions, loss of self-control, shallow breathing, slow heartbeat, or loss of consciousness may occur, which can be life-threatening.
In most cases, the symptoms of low blood sugar disappear very quickly when the patient consumes some sugar, e.g., glucose tablets, sugar cubes, or drinks sweet juice or sweetened tea.
Therefore, it is essential to always carry some sugar products (glucose tablets, sugar cubes).
It should be remembered that artificial sweeteners are not effective. Contact a doctor or the nearest hospital if consuming sugar does not help, if symptoms return, or persist for a long time.
Symptoms of low blood sugar may not occur, may be mild, or may develop very slowly, or the patient may not be aware that their blood sugar levels have decreased. This can happen when the patient is elderly and taking certain medicines (e.g., those acting on the central nervous system and beta-adrenolytics).
In stressful situations (e.g., accidents, surgeries, infections, fever, etc.), the doctor may temporarily change the treatment to insulin therapy.
Symptoms of high blood sugar (hyperglycemia) may occur when gliclazide has not yet sufficiently lowered blood sugar levels, if the patient does not follow the treatment plan prescribed by the doctor, if they use products containing St. John's Wort (Hypericum perforatum) (see section "Diagen and other medicines"), or in specific stressful situations. This may include thirst, frequent urination, dry mouth, dry, itchy skin, skin infections, and decreased activity.
If these symptoms occur, the patient must contact their doctor or pharmacist.
If in the past, someone in the patient's family or the patient themselves has been diagnosed with a congenital deficiency of glucose-6-phosphate dehydrogenase (G6PD) (abnormal red blood cells), a decrease in hemoglobin levels and breakdown of red blood cells (hemolytic anemia) may occur. Before taking this medicine, the patient should consult their doctor.
In patients with porphyria (a genetic disease characterized by the accumulation of porphyrins or their precursors in the body), cases of porphyria exacerbation have been reported after taking certain other sulfonylurea derivatives.
Children and adolescents
Diagen is not recommended for use in children and adolescents due to the lack of data.
Diagen and other medicines
Tell your doctor or pharmacist about all medicines you are taking or have recently taken, as well as any medicines you plan to take.
Do not takeDiagen if you are taking miconazole for the treatment of fungal infections (see section "When not to take Diagen").
The blood sugar-lowering effect of gliclazide may be enhanced, and symptoms of low blood sugar may occur when taking one of the following medicines:
- other medicines used to treat high blood sugar (insulin or oral antidiabetic medicines, such as acarbose, thiazolidinediones (e.g., pioglitazone), metformin, GLP-1 receptor agonists (e.g., exenatide, liraglutide, lixisenatide, or albiglutide))
- antibiotics (e.g., sulfonamides, clarithromycin)
- medicines used to treat high blood pressure or heart failure (beta-adrenolytics, ACE inhibitors, such as captopril or enalapril)
- medicines used to treat fungal infections (miconazole, fluconazole)
- medicines used to treat stomach or duodenal ulcers (H2 receptor antagonists)
- medicines used to treat depression (MAO inhibitors)
- pain or anti-rheumatic medicines (phenylbutazone, anti-inflammatory medicines)
- medicines containing alcohol
- medicines used to treat high cholesterol (fibrates)
- medicines used to treat fever or pain (salicylates)
The blood sugar-lowering effect of gliclazide may be reduced, and symptoms of high blood sugar may occur when taking one of the following medicines:
- medicines used to treat central nervous system disorders (chlorpromazine)
- anti-inflammatory medicines (corticosteroids). Self-monitoring of blood glucose is essential when taking this medicine, especially at the beginning of treatment
- medicines used to treat asthma or used during childbirth (intravenously administered salbutamol, rytodryna, terbutalina). Self-monitoring of blood glucose is essential when taking these medicines
- medicines used to treat breast diseases, heavy menstrual bleeding, and endometriosis (danazol). Self-monitoring of blood glucose and urine is essential when taking these medicines
- products containing St. John's Wort (Hypericum perforatum) used to treat mild depression
When taking Diagen with fluoroquinolone antibiotics, especially in elderly patients, disturbances in blood sugar levels (low and high blood sugar) may occur.
Diagen may increase the effect of anticoagulant medicines (e.g., warfarin).
Consult your doctor before starting to take other medicines. If you are going to the hospital, inform the medical staff that you are taking Diagen.
Diagen and alcohol
Drinking alcohol while taking Diagen is not recommended, as it may disrupt diabetes control, leading to diabetic coma.
Pregnancy and breastfeeding
Pregnancy
Diagen should not be taken during pregnancy.
Breastfeeding
Diagen should not be taken during breastfeeding.
If you are pregnant or breastfeeding, think you may be pregnant, or plan to have a child, consult your doctor or pharmacist before taking this medicine. The doctor may recommend more suitable treatment.
Driving and using machines
Diagen has no influence or negligible influence on the ability to drive and use machines. However, if blood sugar levels are too low (hypoglycemia) or too high (hyperglycemia), or if vision is impaired due to abnormal blood sugar levels, the ability to concentrate or react may be impaired. Such symptoms may occur more frequently at the beginning of treatment with Diagen.
Remember that you may pose a risk to yourself or others (e.g., while driving or operating machines). Ask your doctor about the possibility of driving:
- if low blood sugar (hypoglycemia) occurs frequently;
- if symptoms of low blood sugar (hypoglycemia) are very mild or absent.
3. How to take Diagen
Take this medicine always as directed by your doctor or pharmacist. In case of doubt, consult your doctor or pharmacist.
The dose is determined by the doctor, depending on blood sugar levels and urine tests.
Any changes related to external factors (e.g., weight loss, lifestyle changes, stress) or improvement in blood sugar control may require a change in gliclazide doses.
The recommended dose is from half a tablet to 2 tablets (from 30 mg to a maximum of 120 mg) taken once during breakfast. The dose depends on the body's response to treatment.
The initial dose is usually 30 mg once a day. If blood glucose levels are not adequately controlled, the doctor may increase the dose at subsequent intervals, usually not more frequently than every 1 month.
In combination therapy with Diagen and metformin, alpha-glucosidase inhibitor, or insulin, the appropriate dose of each medicine will be individually determined by the doctor.
Consult your doctor or pharmacist if you feel that the effect of Diagen is too strong or too weak.
The tablet can be divided into equal doses.
Swallow half a tablet or one (or more) tablets once. Do not chew or crush.
Take the tablet(s) with a glass of water during breakfast (preferably at the same time every day).
Always eat a meal after taking the tablet(s).
Taking a higher dose of Diagen than recommended
In case of taking too many tablets, the patient may experience low blood sugar (hypoglycemia), and should immediately contact their doctor or go to the nearest hospital.
Symptoms of overdose are symptoms of low blood sugar (hypoglycemia) and are described in section 2. In such situations, eating sugar (4 to 6 sugar cubes) or drinking a sweet drink, followed by a snack or meal, may help. If the patient is unconscious, immediately inform a doctor and call emergency services. The same applies if someone, e.g., a child, has taken this medicine by mistake. Unconscious patients should not be given food or drink.
Make sure that someone who can call a doctor in case of an emergency is always informed beforehand.
Missing a dose of Diagen
It is essential to take the medicine every day, as regularly taken medicine works better.
However, if you miss a dose of Diagen, take the next dose at the usual time. Do not take a double dose to make up for the missed dose.
Stopping treatment with Diagen
Since diabetes treatment usually lasts a lifetime, consult your doctor before stopping treatment with this medicine. Stopping treatment may cause an increase in blood sugar levels (hyperglycemia).
If you have any further doubts about taking this medicine, consult your doctor or pharmacist.
4. Possible side effects
Like all medicines, Diagen can cause side effects, although not everybody gets them.
The most commonly observed adverse reaction is low blood sugar (hypoglycemia).
Objective and subjective symptoms are described in the section "Warnings and precautions".
If these symptoms are left untreated, they may lead to drowsiness, loss of consciousness, or coma. If the decrease in blood sugar levels is significant or prolonged, even if it is temporarily controlled by administering sugar, you should immediately consult a doctor.
Stop taking the medicine and immediately inform your doctor if you experience any of the following side effects:
- decrease in the number of white and red blood cells and platelets (may cause fatigue, easy bruising, fever, frequent nosebleeds, and increased risk of infection, e.g., pharyngitis, oral ulcers)
- liver function disorders, such as hepatitis, which may cause nausea (nausea), vomiting, loss of appetite, fever, itching, yellowing of the skin and eyes, dark urine, pale stools, which may lead to liver failure
- purple spots and patches on the skin; skin ulcers most often on the legs, buttocks, or torso; blisters on the skin; hives, which may last longer than 24 hours, and open sores with tissue death
- severe skin reactions, such as Stevens-Johnson syndrome with widespread skin blistering and bleeding in the area of the lips, eyes, mouth, nose, and genitals, as well as toxic epidermal necrolysis, which may cause rash, blisters, or skin peeling
- drug reaction, which may include a red rash with palpable nodules, elevated temperature, lymph node enlargement (e.g., under the arms), and general malaise. Blood tests may show changes in liver function or changes in the number of certain types of blood cells
- swelling of the face, lips, tongue, or throat, difficulty breathing or swallowing
Other side effects
Very rare: may occur in 1 in 10,000 people
- decrease in the number of red blood cells, which may cause pallor, fatigue, headache, dizziness
- skin reactions, such as rash, redness, itching, hives, red elevated rash, blisters
- increased liver enzyme activity, which may be visible in blood tests.
Frequency not known: frequency cannot be estimated from the available data
- vision disorders due to changes in blood sugar levels
- decrease in blood sodium levels (hyponatremia) These symptoms usually disappear after stopping treatment.
Gastrointestinal disorders
Abdominal pain, nausea (nausea), vomiting, indigestion, diarrhea, constipation have been observed. These reactions are less frequent when Diagen is taken with breakfast, as recommended.
Reporting side effects
If you experience any side effects, including those not listed in this leaflet, tell your doctor or pharmacist. Side effects can be reported directly to the Department of Drug Safety Monitoring of the Office for Registration of Medicinal Products, Medical Devices, and Biocidal Products, Al. Jerozolimskie 181C, 02-222 Warsaw, tel.: 22 49 21 301, fax: 22 49 21 309,
website: https://smz.ezdrowie.gov.pl
Side effects can also be reported to the marketing authorization holder.
By reporting side effects, you can help provide more information on the safety of this medicine.
5. How to store Diagen
Keep the medicine out of the sight and reach of children.
Do not use this medicine after the expiry date stated on the carton, bottle, or blister after the expiry date (EXP). The expiry date refers to the last day of the month.
Bottles:Use within 100 days of opening the packaging.
There are no special precautions for storing the medicine.
Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines that are no longer needed. This will help protect the environment.
6. Contents of the packaging and other information
What Diagen contains
The active substance is gliclazide. Each modified-release tablet contains 60 mg of gliclazide.
Other ingredients of the medicine are hypromellose, microcrystalline cellulose, magnesium stearate.
What Diagen looks like and contents of the pack
Diagen is a white to almost white, elongated, biconvex tablet with "M" embossed on the left side of the break line on one side of the tablet and "GL" on the left side of the break line and "60" on the right side on the other side of the tablet. The tablet can be divided into equal doses.
Diagen is available in blisters containing 10, 30, 30 x 1 (single doses), 60, or 90, 90 x 1 (single doses) tablets and in bottles of 30, 60, or 90, 100 tablets.
Not all pack sizes may be marketed.
Marketing authorization holder:
Viatris Limited
Damastown Industrial Park
Mulhuddart, Dublin 15
DUBLIN
Ireland
Manufacturer/Importer:
McDermott Laboratories Limited trading as Gerard Laboratories
35/36 Baldoyle Industrial Estate
Grange Road, Dublin 13
Ireland
Mylan Hungary Kft
H-2900 Komárom
Mylan utca 1
Hungary
To obtain more detailed information about the medicine and its names in the Member States of the European Economic Area, contact the representative of the marketing authorization holder:
Viatris Healthcare Sp. z o.o.
Tel: +48 22 546 64 00
Date of last revision of the leaflet:March 2025

- Country of registration
- Dosage formTablets, 60 mg
- ATC codeA10BB09
- Active substance
- Prescription requiredYes
- ImporterMcDermott Laboratories Limited (t.a. Gerard Laboratories) Mylan Hungary Kft.
- This information is for reference only and does not constitute medical advice. Always consult a doctor before taking any medication. Oladoctor is not responsible for medical decisions based on this content.
- Alternatives to DiagenDosage form: Tablets, 30 mgActive substance: gliclazideManufacturer: Balkanpharma-Dupnitsa ADPrescription requiredDosage form: Tablets, 60 mgActive substance: gliclazideManufacturer: Balkanpharma-Dupnitsa ADPrescription not requiredDosage form: Tablets, 80 mgActive substance: gliclazidePrescription required
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Frequently Asked Questions
Diagen requires a prescription in Poland. You can check with a doctor online whether this medicine may be appropriate for your situation.
The active ingredient in Diagen is gliclazide. This information helps identify medicines with the same composition but different brand names.
Diagen is manufactured by McDermott Laboratories Limited (t.a. Gerard Laboratories) Mylan Hungary Kft.. Pharmacy brands and packaging may differ depending on the distributor.
Doctors such as Family doctors, Psychiatrists, Dermatologists, Cardiologists, Endocrinologists, Gastroenterologists, Pulmonologists, Nephrologists, Rheumatologists, Hematologists, Infectious disease physicians, Allergists, Geriatricians, Paediatricians, Oncologists may assess whether Diagen is appropriate, depending on your situation and local regulations. You can book an online consultation to discuss your symptoms and possible next steps.
Spain has a well-developed healthcare infrastructure across major cities such as Madrid, Barcelona, Valencia, and Seville. Pharmacies are widely available and operate under strict regulations, ensuring access to prescribed medications.
You can buy Diagen in Madrid, Barcelona, Seville, or Valencia at any local pharmacy with a valid prescription.
To obtain a prescription, you can use Oladoctor:
Other medicines with the same active substance (gliclazide) include Clazicon, Clazicon, Diabrezide. These may have different brand names or formulations but contain the same therapeutic ingredient. Always consult a doctor before switching or starting a new medicine.










