Siofor 500

Leaflet accompanying the packaging: patient information

SIOFOR 500, 500 mg, coated tablets

Metformin hydrochloride
For use in children over 10 years of age and adults

Read the leaflet carefully before taking the medicine, as it contains important information for the patient.

• Keep this leaflet, you may need to read it again.
• If you have any further questions, ask your doctor or pharmacist.
• This medicine has been prescribed for you only. Do not pass it on to others. It may harm them, even if their symptoms are the same as yours.
• If you experience any side effects, including any not listed in this leaflet, please tell your doctor or pharmacist. See section 4.

Table of contents of the leaflet:

• 1. What is Siofor 500 and what is it used for
• 2. Important information before taking Siofor 500
• 3. How to take Siofor 500
• 4. Possible side effects
• 5. How to store Siofor 500
• 6. Contents of the pack and other information

1. What is Siofor 500 and what is it used for

Siofor 500 contains metformin, a substance used to treat diabetes. It belongs to a group of medicines called biguanides.
Insulin is a hormone produced by the pancreas that allows the body to take up glucose (sugar) from the blood. The body uses glucose to produce energy or stores it for later use.
In diabetic patients, the pancreas does not produce enough insulin or the body is unable to use the produced insulin properly. This leads to an excessive increase in blood glucose levels. Siofor 500 helps to lower blood glucose levels to as close to normal as possible.
In adults with overweight, long-term use of Siofor 500 also reduces the risk of complications associated with type 2 diabetes. Taking Siofor 500 is associated with stabilization or moderate weight loss.

What is Siofor 500 used for

Siofor 500 is used for:

• treatment of type 2 diabetes, especially in patients with overweight, to achieve proper control of blood glucose levels.
• prevention of type 2 diabetes in patients with pre-diabetic conditions.

Adults with type 2 diabetes can take Siofor 500 as monotherapy or with other anti-diabetic medicines (oral or insulin).
Children over 10 years of age and adolescents with type 2 diabetes can take Siofor 500 as monotherapy or in combination with insulin.
During treatment with Siofor 500, the patient should follow a diet and engage in physical activity.

2. Important information before taking Siofor 500

When not to take Siofor 500

• if the patient is allergic to metformin or any of the other ingredients of this medicine (listed in section 6)
• if the patient has significantly reduced kidney function
• in case of liver function disorders
• if the patient has uncontrolled diabetes, such as severe hyperglycemia (high blood sugar), nausea, vomiting, diarrhea, sudden weight loss, lactic acidosis (see "Risk of lactic acidosis" below) or diabetic ketoacidosis. Diabetic ketoacidosis is a condition in which substances called ketone bodies accumulate in the blood and can lead to diabetic pre-coma. Its symptoms include: abdominal pain, rapid and deep breathing, drowsiness or unusual fruity breath odor
• in case of excessive water loss from the body (dehydration), e.g. due to prolonged or severe diarrhea or repeated vomiting. Dehydration can lead to kidney function disorders, which can threaten the occurrence of lactic acidosis (see below "Warnings and precautions")
• in case of severe infection, such as affecting the lungs, bronchi or kidneys. Severe infections can lead to kidney function disorders, which can threaten the occurrence of lactic acidosis (see below "Warnings and precautions")
• in case of treatment of acute heart failure or recently suffered heart attack, severe circulatory disorders (such as shock) or breathing difficulties. This may cause tissue hypoxia, which can threaten the occurrence of lactic acidosis (see below "Warnings and precautions"),
• in case of alcohol abuse.

Warnings and precautions

Before starting treatment with Siofor 500, discuss it with your doctor.

You must consult a doctor if necessary:

• if a radiological examination or examination requiring the injection of a contrast agent containing iodine into the bloodstream is to be performed,
• if a major surgical procedure is to be performed. If the patient is to undergo surgery, they must not take Siofor 500 during the procedure and for some time after it. The doctor will decide when the patient should stop and resume treatment with Siofor 500. It is essential to follow the doctor's instructions carefully.
• 500. It is essential to follow the doctor's instructions carefully.

Risk of lactic acidosis

Siofor 500 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 (see more information below), 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.

Temporarily discontinue use of Siofor 500 if the patient has a condition that may be associated with dehydration

(significant water loss from the body), such as severe vomiting, diarrhea, fever, exposure to high temperatures, or if the patient drinks less fluid than usual. The patient should consult their doctor for more detailed instructions.

Discontinue use of Siofor 500 and contact a doctor or the nearest hospital immediately if the patient experiences any symptoms of lactic acidosis

, as this condition can lead to coma.
Symptoms of lactic acidosis include:

• vomiting,
• abdominal pain (abdominal pain),
• muscle cramps,
• general poor condition with severe fatigue,
• breathing difficulties,
• decreased body temperature and slowed heart rate.

Lactic acidosis is a life-threatening condition that requires immediate hospital treatment.

Consult a doctor immediately for further instructions if:

• the patient has a genetically inherited disease affecting mitochondria (energy-producing structures in cells), such as MELAS syndrome (mitochondrial encephalopathy, myopathy, lactic acidosis, and stroke-like episodes) or maternally inherited diabetes and deafness.
• the patient experiences any of the following symptoms after starting metformin: seizures, impaired cognitive abilities, difficulty moving, signs of nerve damage (e.g. pain or numbness), migraine, or hearing loss.

During treatment with Siofor 500, the doctor will monitor the patient's kidney function at least once a year or more frequently if the patient is elderly and/or has deteriorating kidney function.
Siofor 500 itself does not cause hypoglycemia (low blood sugar).
However, there is a risk of hypoglycemia if Siofor 500 is used in combination with other anti-diabetic medicines that can cause hypoglycemia (such as sulfonylurea derivatives, insulin, meglitinides). If symptoms of hypoglycemia occur, such as weakness, dizziness, increased sweating, rapid heartbeat, vision disturbances, or difficulty concentrating, eating or drinking something containing sugar usually helps.

Siofor 500 and other medicines

If the patient is to be injected with a contrast agent containing iodine into the bloodstream, for example, for an X-ray examination or computed tomography, they must discontinue Siofor 500 before or at the latest at the time of such injection.The doctor will decide when the patient should stop and resume treatment with Siofor 500 (see above: "You must consult a doctor if necessary:").
The patient should tell their doctor about all medicines they are currently taking or have recently taken, as well as any medicines they plan to take at the same time as Siofor 500.
The patient may require more frequent blood glucose checks and kidney function assessments or modification of the Siofor 500 dose by the doctor. It is especially important to inform about the following medicines:

• diuretics,
• medicines used to treat pain and inflammation (NSAIDs and COX-2 inhibitors, such as ibuprofen and celecoxib),
• certain medicines used to treat high blood pressure (ACE inhibitors and angiotensin II receptor antagonists),
• beta-2 adrenergic receptor agonists, such as salbutamol or terbutaline (used to treat asthma),
• corticosteroids (used to treat various diseases, such as severe skin inflammation or asthma),
• other medicines used to treat diabetes,
• medicines that may change the level of Siofor 500 in the blood, especially if the patient has kidney function disorders (such as verapamil, rifampicin, cimetidine, dolutegravir, ranolazine, trimethoprim, vandetanib, isavuconazole, crizotinib, olaparib).

Siofor 500 and alcohol

The patient should avoid consuming excessive amounts of alcohol while taking Siofor 500, as this may increase the risk of lactic acidosis (see section "Warnings and precautions"), especially in patients with liver function disorders or malnutrition.
This also applies to medicines containing alcohol.

Pregnancy and breastfeeding

If the patient is pregnant or breastfeeding, thinks they may be pregnant, or plans to have a child, they should consult their doctor before taking this medicine.
Pregnancy
During pregnancy, diabetes treatment requires the use of insulin.
Breastfeeding
This medicine is not recommended during breastfeeding.

Driving and using machines

Siofor 500, used as the only anti-diabetic medicine, does not cause hypoglycemia (symptoms of low blood sugar). This means it does not affect the ability to drive or operate machines.
However, the patient should be particularly careful if they are taking Siofor 500 at the same time as other anti-diabetic medicines that can cause hypoglycemia (such as sulfonylurea derivatives, insulin, meglitinides). Symptoms of hypoglycemia include: weakness, dizziness, increased sweating, rapid heartbeat, vision disturbances, or difficulty concentrating.
If such symptoms occur, the patient should not drive or operate machines.

3. How to take Siofor 500

This medicine should always be taken exactly as prescribed by the doctor or pharmacist. If the patient has any doubts, they should consult their doctor or pharmacist.
Siofor 500 does not replace the benefits of a healthy lifestyle. The patient should continue to follow all the doctor's recommendations regarding diet and regular physical exercise.
The recommended dose is:
For adults, the usual starting dose is 1 coated tablet of Siofor 500 2 to 3 times a day (corresponding to 1000 mg or 1500 mg of metformin hydrochloride per day) or 850 mg of metformin hydrochloride 2 to 3 times a day (this dose cannot be achieved with Siofor 500).
The maximum daily dose is 2 coated tablets of Siofor 500 3 times a day (corresponding to 3000 mg of metformin hydrochloride per day).
If the patient has kidney function disorders, the doctor may prescribe a lower dose.

Use in children and adolescents

For children over 10 years of age and adolescents, the usual starting dose is 1 coated tablet of Siofor 500 once a day (corresponding to 500 mg of metformin hydrochloride per day) or 850 mg of metformin hydrochloride once a day (this dose cannot be achieved with Siofor 500).
The maximum daily dose is 2000 mg, given in 2 or 3 divided doses.
Treatment of children over 10 to 12 years of age is recommended by the doctor only in justified cases, as experience with the use of the medicine in this age group is limited.
If the patient is also taking insulin, the doctor will inform them how to start taking Siofor 500.

Pre-diabetic condition (in monotherapy in adults with normal kidney function)

The recommended starting dose for patients with pre-diabetic conditions is 1 coated tablet (500 mg or 850 mg) once a day with a meal or after a meal.
The dose usually used in patients with pre-diabetic conditions is 1 coated tablet (500 mg or 850 mg) twice a day with a meal or after a meal.
Gradual dose increase may improve gastrointestinal tolerance.
The doctor will assess whether treatment should be continued based on regular blood glucose tests and risk factors.

Treatment monitoring

• The doctor will prescribe regular blood glucose tests and adjust the Siofor 500 dose based on blood glucose levels. The patient should regularly visit their doctor for check-ups. This is especially important for children and adolescents or elderly patients.
• The doctor will check the patient's kidney function at least once a year during treatment with Siofor 500. More frequent checks may be necessary for elderly patients or if the patient's kidneys are not functioning properly.

How to take Siofor 500 coated tablets

The patient should take the tablets with a meal or after a meal. This will help avoid gastrointestinal side effects.
The patient should not crush or chew the tablets. They should swallow the tablet with a glass of water.

• In case of taking one dose per day, it should be taken in the morning (breakfast)
• In case of taking two divided doses per day, they should be taken in the morning (breakfast) and evening (dinner)
• In case of taking three divided doses per day, they should be taken in the morning (breakfast), at noon (lunch), and evening (dinner) If after some time the patient feels that the effect of Siofor 500 is too strong or too weak, they should consult their doctor or pharmacist.

Use of a higher than recommended dose of Siofor 500

In case of taking a higher dose of Siofor 500 than recommended, lactic acidosis may occur.
Symptoms of lactic acidosis are: vomiting, abdominal pain (abdominal pain) with muscle cramps, poor general condition with severe fatigue, and breathing difficulties.
Other symptoms include decreased body temperature and slowed heart rate. If such symptoms occur, the patient may require immediatehospital treatment, as lactic acidosis can lead to coma.
Immediatelycontact a doctor or go to the nearest hospital.

Missing a dose of Siofor 500

The patient should not take a double dose to make up for a missed dose. They should take the next dose according to the planned dosing schedule.
If the patient has any further doubts about taking this medicine, they should consult their doctor or pharmacist.

4. Possible side effects

Like all medicines, Siofor 500 can cause side effects, although not everybody gets them.
The following side effects may occur:

Important side effects or symptoms that the patient should know about and precautions to take if they occur:

Siofor 500 may very rarely cause (may occur in up to 1 in 10,000 patients) a very serious side effect called lactic acidosis (see section "Warnings and precautions"). If this occurs in the patient, they should stop takingSiofor 500 and contact a doctor or the nearest hospital immediately, as lactic acidosis can lead to coma.

Other possible side effects

Very common side effects (may occur in more than 1 in 10 patients)

• gastrointestinal disorders, such as: nausea, vomiting, diarrhea, abdominal pain (abdominal pain), and loss of appetite. These side effects usually occur at the beginning of treatment with Siofor 500. It may be helpful to divide the doses throughout the day and take the tablets with a meal or immediately after a meal. If the symptoms do not disappear, the patient should discontinue Siofor 500 and tell their doctor.

Common side effects (may occur in less than 1 in 10 patients)

• taste disorders
• decreased or low levels of vitamin B in the blood (symptoms may include extreme fatigue, pain, and redness of the tongue, numbness or pale or yellowish skin). The doctor may prescribe several tests to find the cause of the symptoms, as some of them may also be caused by diabetes or other unrelated health problems.

Very rare side effects (may occur in less than 1 in 10,000 patients)

• skin reactions such as skin redness, itching, or itchy rash
• abnormal liver function test results or hepatitis (hepatitis, which can cause fatigue, loss of appetite, weight loss, with or without yellowing of the skin and whites of the eyes). If such symptoms occur, the patient should stop takingSiofor 500 and tell their doctor.

Additional side effects in children and adolescents

Limited data in children and adolescents have shown that side effects were similar in type and severity to those reported in adults.

Reporting side effects

If the patient experiences any side effects, including any not listed in this leaflet, they should tell their doctor or pharmacist, or nurse.
Side effects can be reported directly to the Department of Adverse Reaction Monitoring of Medicinal Products, Medical Devices, and Biocidal Products
Al. Jerozolimskie 181C
02-222 Warsaw
Phone: +48 22 49 21 301
Fax: +48 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, more information can be collected on the safety of the medicine.

5. How to store Siofor 500

The medicine should be stored out of sight and reach of children. If a child is being treated with Siofor 500, parents and caregivers should supervise how the medicine is taken.
Do not use this medicine after the expiry date stated on the outer packaging and blister after the "EXP" abbreviation. The expiry date refers to the last day of the month.
There are no special precautions for storage.
Medicines should not be disposed of via wastewater or household waste. The patient should ask their pharmacist how to dispose of medicines that are no longer needed. This will help protect the environment.

6. Contents of the pack and other information

What Siofor 500 contains

• The active substance of the medicine is metformin hydrochloride.
• One coated tablet contains 500 mg of metformin hydrochloride, which corresponds to 390 mg of metformin.
• The other ingredients are: Tablet core: hypromellose, povidone, magnesium stearate. Tablet coating: hypromellose, macrogol 6000, titanium dioxide (E 171).

What Siofor 500 looks like and contents of the pack

White, round, biconvex coated tablets in blisters of transparent PVC film and aluminum foil.
Siofor 500 is available in packs containing: 10, 30, 60, 90, or 120 coated tablets.
Not all pack sizes may be marketed.

Marketing authorization holder:

BERLIN – CHEMIE AG
(Menarini Group)
Glienicker Weg 125
12489 Berlin, Germany

Manufacturer:

BERLIN – CHEMIE AG
Glienicker Weg 125
12489 Berlin, Germany
To obtain more detailed information about this medicine, the patient should contact the local representative of the marketing authorization holder:
Berlin-Chemie/Menarini Polska Sp. z o.o.
Phone: + 48 22 566 21 00
Fax: + 48 22 566 21 01

Date of last revision of the leaflet: 03/2025