Siofor Xr 500 mg

Package Leaflet: Information for the Patient

Siofor XR 500 mg, 500 mg, prolonged-release tablets

Siofor XR 750 mg, 750 mg, prolonged-release tablets

Siofor XR 1000 mg, 1000 mg, prolonged-release tablets

Metformin hydrochloride

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

• Keep this package 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 those not listed in this package leaflet, please inform your doctor or pharmacist. See section 4.

Table of Contents of the Package Leaflet:

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

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

Siofor XR contains the active substance metformin hydrochloride, which belongs to a group of medicines called biguanides and is used to treat type 2 diabetes (non-insulin-dependent).
Siofor XR is used to treat patients with type 2 diabetes (also called non-insulin-dependent diabetes) who are not adequately controlled by diet and exercise alone. Insulin is a hormone that allows the body's cells to take up glucose from the blood to produce energy or store it for later use. In patients with type 2 diabetes, the pancreas does not produce enough insulin or the body does not respond properly to the insulin produced. This leads to a buildup of glucose in the blood, which can cause a range of serious, long-term complications. Therefore, it is important that you continue to take your medicine, even if you do not feel unwell.
Siofor XR makes the body more sensitive to insulin and helps restore the normal way the body uses glucose.
Taking Siofor XR is associated with both weight stabilization and moderate weight loss.
Siofor XR is designed to release the active substance slowly in the body and is therefore different from many other types of tablets containing metformin hydrochloride.

2. Important information before taking Siofor XR

When not to take Siofor XR:

• if you are allergic to metformin hydrochloride or any of the other ingredients of this medicine (listed in section 6). An allergic reaction may cause a rash, itching, or difficulty breathing,
• in case of liver dysfunction,
• if you have significantly reduced kidney function,
• if you have 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 coma. Its symptoms include abdominal pain, rapid and deep breathing, drowsiness, or a fruity odor from the mouth,
• in case of excessive fluid loss from the body (dehydration), which may occur in case of prolonged or severe diarrhea or repeated vomiting. Dehydration can lead to kidney dysfunction, which can increase the risk of lactic acidosis (see "Warnings and precautions" below),
• in case of severe infection, such as those affecting the lungs, bronchi, or kidneys. Severe infections can lead to kidney dysfunction, which can increase the risk of lactic acidosis (see "Warnings and precautions" below),
• in case of treatment for acute heart failure or recent myocardial infarction, severe circulatory disorders, or breathing difficulties. This can cause tissue hypoxia, which can increase the risk of lactic acidosis (see "Warnings and precautions" below),
• in case of alcohol abuse.
• if you are under 18 years old.

Warnings and precautions

Before starting to take Siofor XR, discuss it with your doctor or pharmacist.

Risk of lactic acidosis

Siofor XR may cause a very rare but very serious side effect called lactic acidosis, especially if you have kidney problems. The risk of lactic acidosis also increases in case of uncontrolled diabetes, severe infection, prolonged fasting, or alcohol consumption, dehydration (see more information below), liver dysfunction, and any conditions in which a part of the body is not adequately supplied with oxygen (e.g., acute severe heart disease).
If any of the above conditions apply to you, you should consult your doctor for more detailed instructions.

You should temporarily stop taking Siofor XR if you have a condition that may lead to dehydration

(significant fluid 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.

You should stop taking Siofor XR and contact your doctor immediately or go to the nearest hospital if you experience any symptoms of lactic acidosis

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

• vomiting,
• abdominal pain (pain in the abdominal cavity),
• 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 hospital treatment.

You should contact your doctor immediately for further instructions if:

• you have a genetically inherited disease affecting the 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.
• after starting metformin, you experience any of the following symptoms: seizures, cognitive impairment, difficulty moving, symptoms indicating nerve damage (e.g., pain or numbness), migraine, and hearing loss.

If you are to undergo a major surgical procedure, YOU MUST STOPtaking Siofor XR during the procedure and for some time after it. Your doctor will decide when you should stop and resume treatment with Siofor XR.
During treatment with Siofor XR, your doctor will monitor your kidney function at least once a year or more often if you are elderly and/or have impaired kidney function.
Tablet residues may appear in the stool. Do not be concerned, as this is normal when taking this type of tablet.
You should continue to follow the dietary recommendations given by your doctor and ensure that carbohydrates are consumed regularly throughout the day.
Do not stop taking this medicine without consulting your doctor.

Siofor XR and other medicines:

If you are to receive an iodine-containing contrast agent intravenously, for example, for an X-ray examination or computed tomography, YOU MUST STOPtaking Siofor XR before or at the latest at the time of such administration. Your doctor will decide when you should stop and resume treatment with Siofor XR.
Tell your doctor or pharmacist about all medicines you are taking or have recently taken, as well as any medicines you plan to take.
You may need more frequent monitoring of blood glucose levels and kidney function or dose adjustment of Siofor XR by your doctor. It is especially important to inform about the following medicines:

• diuretics (such as furosemide),
• 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),
• corticosteroids such as prednisolone, mometasone, beclomethasone,
• sympathomimetic medicines, including epinephrine and dopamine used to treat myocardial infarction and low blood pressure. Epinephrine is also contained in some dental anesthetics.
• medicines that may change the level of Siofor XR in the blood, especially if you have kidney problems (such as verapamil, rifampicin, cimetidine, dolutegravir, ranolazine, trimethoprim, vandetanib, isavuconazole, crizotinib, olaparib).

Taking Siofor XR with alcohol

You should avoid consuming excessive amounts of alcohol while taking Siofor XR, as this may increase the risk of lactic acidosis (see "Warnings and precautions").

Pregnancy, breastfeeding, and fertility

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.
This medicine is not recommended for breastfeeding women or those planning to breastfeed.
Before taking any medicine, consult your doctor or pharmacist.

Driving and using machines

Siofor XR, when used as the only antidiabetic medicine, does not cause hypoglycemia (symptoms of low blood sugar, such as fainting, disorientation, and increased sweating). This means it does not affect your ability to drive or use machines.
However, you should be aware that taking Siofor XR with other antidiabetic medicines may cause hypoglycemia. In this case, you should be particularly cautious while driving or using machines.

Siofor XR contains sodium

This medicine contains less than 1 mmol (23 mg) of sodium per tablet, which means it is essentially "sodium-free".

3. How to take Siofor XR

Your doctor may prescribe Siofor XR as the only antidiabetic medicine (monotherapy) or in combination with other oral antidiabetic medicines or insulin.
This medicine should always be taken exactly as your doctor or pharmacist has told you.
If you are not sure, ask your doctor or pharmacist.

Recommended dose

The usual starting dose is 500 mg of Siofor XR per day. After about 2 weeks of taking Siofor XR, your doctor will order a blood sugar test and adjust the dose of the medicine.
The maximum daily dose is 2000 mg of Siofor XR.
If you have impaired kidney function, your doctor may prescribe a lower dose.
It is usually taken once a day during the evening meal.
In some cases, your doctor may recommend taking the tablet twice a day. You should always take the tablet with a meal.
Swallow the tablet whole with a glass of water, do not chew.

Taking a higher dose of Siofor XR than recommended

Accidental ingestion of a larger number of tablets than recommended should not be a cause for concern, but if unusual symptoms occur, you should contact your doctor. In case of significant overdose, lactic acidosis may occur. The symptoms of lactic acidosis are non-specific and include vomiting, abdominal pain (pain in the abdominal cavity) with muscle cramps, poor general condition with severe fatigue, and breathing difficulties. Further symptoms include decreased body temperature and slowed heart rate.
If you experience any of these symptoms, STOP TAKING Siofor XR IMMEDIATELY AND CONTACT YOUR DOCTOR OR GO TO THE NEAREST HOSPITAL, as lactic acidosis can lead to coma.

Missing a dose of Siofor XR

You should take the next dose as soon as possible during a meal. Do not take a double dose to make up for the missed dose.
If you have any further questions about taking this medicine, ask your doctor or pharmacist.

4. Possible side effects

Like all medicines, Siofor XR can cause side effects, although not everybody gets them.

The following side effects may occur:

Siofor XR may very rarely cause (may affect up to 1 in 10,000 people) a very serious side effect called lactic acidosis (see "Warnings and precautions"). If this happens to you, STOP TAKING Siofor XR AND CONTACT YOUR DOCTOR OR THE NEAREST HOSPITAL IMMEDIATELY, as lactic acidosis can lead to coma.
Siofor XR may cause abnormal liver function test results and liver inflammation, which can lead to jaundice (may affect up to 1 in 10,000 people). If you experience yellowing of the eyes and/or skin, CONTACT YOUR DOCTOR IMMEDIATELY.

Other possible side effects, listed by frequency of occurrence:

Very common (may affect more than 1 in 10 people)

• Diarrhea, nausea, vomiting, abdominal pain, or loss of appetite. If you experience these symptoms, do not stop taking the tablets, as they usually resolve within about 2 weeks. It may be helpful to take Siofor XR with a meal or immediately after a meal.

Common (may affect up to 1 in 10 people)

• Taste disturbances.
• Decreased or low levels of vitamin B in the blood (symptoms may include extreme fatigue, pain, and redness of the tongue, or numbness). Your doctor may order 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 (may affect up to 1 in 10,000 people)

• Skin rashes, including redness of the skin, itching, and hives.

Reporting side effects

If you experience any side effects, including those not listed in this package leaflet, please inform your doctor or pharmacist, or nurse.
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
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, you can help provide more information on the safety of this medicine.

5. How to store Siofor XR

Keep this medicine out of the sight and reach of children.
Do not use this medicine after the expiry date stated on the blister and carton after EXP. The expiry date refers to the last day of the month.
There are no special storage precautions for this medicinal product.
Medicines should not be disposed of via wastewater or household waste. Ask your pharmacist how to dispose of medicines no longer required. This will help protect the environment.

6. Contents of the pack and other information

What Siofor XR contains

The active substance is metformin hydrochloride.
Each prolonged-release tablet of Siofor XR 500 mg contains 500 mg of metformin hydrochloride (equivalent to 390 mg of metformin).
Each prolonged-release tablet of Siofor XR 750 mg contains 750 mg of metformin hydrochloride (equivalent to 585 mg of metformin).
Each prolonged-release tablet of Siofor XR 1000 mg contains 1000 mg of metformin hydrochloride (equivalent to 780 mg of metformin).
The other ingredients are magnesium stearate, colloidal silica, sodium carmellose, and hypromellose.

What Siofor XR looks like and contents of the pack

Siofor XR 500 mg prolonged-release tablets are white or almost white, capsule-shaped with the inscription "SR 500" on one side and smooth on the other. The dimensions of the tablet are: length 16.5 mm, width 8.2 mm, thickness 6.1 mm.
Siofor XR 750 mg prolonged-release tablets are white or almost white, capsule-shaped with the inscription "SR 750" on one side and smooth on the other. The dimensions of the tablet are: length 19.6 mm, width 9.3 mm, thickness 6.9 mm.
Siofor XR 1000 mg prolonged-release tablets are white or almost white, oval with the inscription "SR 1000" on one side and smooth on the other. The dimensions of the tablet are: length 22 mm, width 10.5 mm, thickness 8.9 mm.
Siofor XR is available in pack sizes of 15, 30, 60, 90, or 120 prolonged-release tablets in a carton.
Not all pack sizes may be marketed.

Marketing authorization holder and manufacturer:

Berlin-Chemie AG
Glienicker Weg 125
12489 Berlin
Germany
For more detailed information on this medicine, please contact the local representative of the marketing authorization holder:
Berlin-Chemie/Menarini Polska Sp. z o.o.
phone: (22) 566 21 00
fax: (22) 566 21 01

This medicine is authorized in the Member States of the European Economic Area under the following names:

Bulgaria:
Сиофор SR 500 mg, 750 mg, 1000 mg таблетки с удължено освобождаване
Croatia:
Siofor SR 500 mg, 750 mg, 1000 mg tablete s produljenim oslobađanjem
Czech Republic:
Siofor Prolong
Estonia:
Metforal XR
Germany:
Siofor XR 500 mg, 750 mg, 1000 mg Retardtabletten
Hungary:
Meforal XR 500 mg, 750 mg, 1000 mg retard tabletta
Latvia:
Metforal 500 mg, 750 mg, 1000 mg ilgstošās darbības tabletes
Lithuania:
Tivulin 500 mg, 750 mg, 1000 mg pailginto atpalaidavimo tabletės
Poland:
Siofor XR 500 mg, 750 mg, 1000 mg
Portugal:
Romania:
Slovakia:
Siofor XR 500 mg, 750 mg, 1000 mg comprimidos de libertação prolongada
Siofor 500 mg, 750 mg, 1000 mg comprimate cu eliberare prelungită
Siofor SR 500 mg, 750 mg, 1000 mg tablety s predĺženým uvoľňovaním
Slovenia:
Siofor SR 500 mg, 750 mg, 1000 mg tablete s podaljšanim sproščanjem

Date of last revision of the package leaflet: 03/2025