Metformin hydrochloride
This medicine is called Zenofor SR 500 mg, 750 mg, 1000 mg prolonged-release tablets, but in this leaflet it is referred to as Zenofor SR.
Zenofor SR prolonged-release tablets contain metformin hydrochloride as the active substance and belong to a group of medicines called biguanides, used to treat type 2 diabetes (non-insulin-dependent diabetes).
Zenofor SR is used to treat type 2 diabetes, when diet and exercise alone cannot control blood sugar levels.
The medicinal product is intended only for adults.
Insulin is a hormone that allows the body to take up glucose and use it for energy or store it for later use.
In patients with type 2 diabetes, the pancreas does not produce enough insulin or the body is not able to use the produced insulin properly. This leads to an excessive increase in blood glucose levels. Zenofor SR helps to lower blood glucose levels to as normal a level as possible.
Taking Zenofor SR is associated with maintaining weight or moderate weight loss.
Zenofor SR is in the form of prolonged-release tablets, which are specially designed to release the medicine slowly in the body and therefore differ from many other types of metformin-containing tablets.
Risk of lactic acidosis(see symptoms in section 4)
Zenofor SR may cause a very rare but very serious side effect called lactic acidosis, especially if the patient has kidney function disorders. The risk of lactic acidosis increases in case of uncontrolled diabetes, severe infection, prolonged fasting, or alcohol consumption, dehydration, liver function disorders, and any conditions in which a part of the body is not sufficiently supplied with oxygen (e.g., acute severe heart disease).
If any of the above circumstances apply to the patient, they should consult their doctor for more detailed instructions.
If the patient is to undergo a major surgical procedure, they must stop taking Zenofor SR before the procedure and for some time after it. The doctor will decide when the patient should stop and resume treatment with Zenofor SR.
During treatment with Zenofor SR, the doctor will monitor the patient's kidney function
at least once a year or more often if the patient is elderly and (or) has deteriorating kidney function.
If the patient is over 75 years old, it is not recommended to start treatment with Zenofor SR to reduce the risk of developing type 2 diabetes.
It may happen that the tablet coating is visible in the stool. You should not be concerned, as this is normal when taking this type of tablet.
You should follow the dietary recommendations given by your doctor and eat carbohydrates regularly throughout the day.
You should not stop taking this medicine without consulting your doctor.
If the patient is to be injected with a radiographic contrast agentcontaining iodine, the patient must stop taking Zenofor SR before or at the latest at the time of such injection. The doctor will decide when the patient should stop and resume treatment with Zenofor SR.
You should tell your doctor about all medicines you are taking or have recently taken, as well as any medicines you plan to take. You may need more frequent blood glucose monitoring and kidney function tests or a dose adjustment of Zenofor SR by your doctor.
It is especially important to inform your doctor about taking the following medicines:
Consuming excessive amounts of alcohol while taking this medicine may increase the risk of lactic acidosis(see symptoms in section 4).
You should not take Zenofor SR if you are addicted to alcohol.
If you are pregnant, think you may be pregnant, or plan to have a baby, you should consult your doctor, as changes in treatment or blood glucose monitoring may be necessary.
Zenofor SR taken as the only antidiabetic medicinedoes not cause hypoglycemia (symptoms such as fainting, confusion, and excessive sweating), and therefore should not affect the ability to drive or operate machines.
However, if you take Zenofor SR in combination with other antidiabetic medicinesthat may cause hypoglycemia, you should be particularly careful while driving or operating machines.
Your doctor may prescribe Zenofor SR as the only antidiabetic medicine or in combination with other oral antidiabetic medicines or insulin.
Zenofor SR should always be taken according to your doctor's instructions.
In case of doubts, you should consult your doctor or pharmacist.
Treatment usually starts with one tablet once a daytaken with the evening meal.
In some cases, your doctor may recommend taking tablets twice a day, but tablets should always be taken with a meal or some food.
Tablets should be swallowed whole with a glass of water, without chewing.
Treatment usually starts with one Zenofor SR tablet containing 500 mg of metformin taken once a day (1 x 500 mg tablet). After about 2 weeks, based on blood glucose measurements, your doctor may adjust the dose. The maximum daily dose of Zenofor SR is 2000 mg (e.g., 4 x 500 mg tablets).
If you have kidney function disorders, your doctor may prescribe a lower dose.
If you accidentally take extra tablets, you should not be concerned. If unusual symptoms occur, you should contact your doctor.
If the overdose is large, it is more likely that lactic acidosis will occur (see symptoms in section 4). You should then stop taking Zenofor SR immediately and contact your doctor or go to the nearest hospital.
A missed tablet should be taken as soon as you remember. You should not take a double dose to make up for a missed dose.
Like all medicines, this medicine can cause side effects, although not everybody gets them.
The following side effects may occur:
You should stop taking Zenofor SRand immediately contact your doctor or go to the nearest hospital if you experience any of the symptoms of lactic acidosis, as this condition can lead to coma.
Symptoms of lactic acidosis include:
You should temporarily stop taking Zenofor SRif you experience symptoms of dehydration(significant water loss from the body), such as severe vomiting, diarrhea, fever, exposure to high temperatures, or if you drink less fluid than usual. You should consult your doctor for more detailed instructions.
Zenofor SR may cause abnormal liver function test results and liver inflammation, which may result in jaundice(may occur in up to 1 in 10,000 patients). If you experience yellowing of the eyes and (or) skin, you should contact your doctor immediately.
Other possible side effectsare listed according to their frequency of occurrence as follows:
Very common(may affect more than 1 in 10 patients):
Common(may affect up to 1 in 10 patients)
Very rare(may affect up to 1 in 10,000 patients)
Reporting side effects
If you experience any side effects, including any side effects not listed in this leaflet, you should tell your doctor or pharmacist, or nurse. Side effects can be reported directly to the Department of Monitoring of Adverse Reactions to Medicinal Products 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 or its representative.
Reporting side effects will help to gather more information on the safety of this medicine.
The medicine should be stored out of sight and reach of children.
Do not use this medicine after the expiry date, which is stated on the packaging after the abbreviation "EXP". The expiry date refers to the last day of the specified month.
There are no special precautions for storage conditions.
If the tablets discolor or show any other signs of deterioration, consult your pharmacist.
Medicines should not be disposed of via wastewater or household waste. You should ask your pharmacist how to dispose of medicines that are no longer needed. This will help protect the environment.
The active substance of Zenofor SR is metformin (in the form of metformin hydrochloride).
Zenofor SR, 500 mg: Each prolonged-release tablet contains 500 mg of metformin hydrochloride, which corresponds to 390 mg of metformin.
Zenofor SR, 750 mg: Each prolonged-release tablet contains 750 mg of metformin hydrochloride, which corresponds to 585 mg of metformin.
Zenofor SR, 1000 mg: Each prolonged-release tablet contains 1000 mg of metformin hydrochloride, which corresponds to 780 mg of metformin.
The other ingredients of the medicine are:
Tablet core:stearic acid, shellac, povidone (K30), colloidal silica, and magnesium stearate
Tablet coating:hypromellose (15 cps), hydroxypropylcellulose, titanium dioxide (E 171), propylene glycol, macrogol 6000, and talc.
Zenofor SR, 500 mg: White, oval, biconvex, film-coated tablets, smooth on both sides, approximately 15.00 × 8.5 mm in size.
Zenofor SR, 750 mg: White, biconvex, film-coated tablets in the shape of a capsule, smooth on both sides, approximately 19.1 × 9.3 mm in size.
Zenofor SR, 1000 mg: White, oval, biconvex, film-coated tablets with a dividing line on one side and smooth on the other, approximately 20.4 × 9.7 mm in size.
The dividing line is not intended for breaking the tablet.
Zenofor SR, 500 mg, is available in packs of 20, 28, 30, 50, 56, 60, 84, 90, 100, 112, 120, 180, or 600 tablets packaged in PVC/PVDC/Aluminum blisters.
Zenofor SR, 750 mg, is available in packs of 14, 20, 28, 30, 50, 56, 60, 84, 90, 100, 112, 120, 180, or 600 tablets packaged in PVC/PVDC/Aluminum blisters.
Zenofor SR, 1000 mg, is available in packs of 14, 20, 28, 30, 50, 56, 60, 84, 90, 100, 112, 120, 180, or 600 tablets packaged in PVC/PVDC/Aluminum blisters.
Not all pack sizes may be marketed.
Zentiva, k.s.
U kabelovny 130
Dolní Měcholupy
102 37 Prague 10
Czech Republic
S.C. ZENTIVA S.A.
B-dul Theodor Pallady nr. 50, Sector 3
Bucharest, code 032266,
Romania
Czech Republic
Mulado Prolong
Poland
Zenofor SR
Hungary
Zenofor 500, 750, 1000 mg retard tablet
Slovakia
Mirovian XR 500 mg/750 mg/1000 mg
Zentiva Polska Sp. z o.o.
ul. Bonifraterska 17
00-203 Warsaw
tel.: +48 22 375 92 00
Date of last revision of the leaflet:February 2025
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