Product Information for the User

Tamoxifeno Viatris 20 mg Film-Coated Tablets

Read this leaflet carefully before you start taking this medicine because it contains important information for you.

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

Tamoxifeno Viatris contains the active ingredient called tamoxifeno and belongs to a group of medicines called antiestrogens.

Oestrogen is in your body and is a natural substance known as a “sex hormone”. Tamoxifeno acts by blocking the effects of oestrogen.

Tamoxifeno Viatris is indicated for certain breast pathologies.

Do not take Tamoxifeno Viatris:

• If you are allergic to tamoxifeno or any of the other components of this medication (listed in section 6).
• If you are pregnant (see “Pregnancy, breastfeeding and fertility”).

Warnings and precautions

Consult your doctor or pharmacist before starting to take Tamoxifeno Viatris.

• The concomitant administration with the following medications should be avoided, as it cannot be ruled out that there will be a reduction in the effects of tamoxifeno: paroxetina, fluoxetina (e.g., antidepressants), bupropión (antidepressant or used to quit smoking), quinidina (used in the treatment of cardiac arrhythmia) and cincalet/cinacalcet (for the treatment of parathyroid gland disorders).
• If you are using a contraceptive method. Consult your doctor about the contraceptive methods you should use, as some may be affected by this drug.
• It is essential to inform your doctor immediately if you experience any unusual vaginal bleeding or other gynecological symptoms (such as pelvic pain or pressure) during treatment with tamoxifeno or at any time thereafter. This is because certain changes may occur inside the uterus (endometrium), some of which may be severe.
• Before starting treatment with this drug, it is essential to inform your doctor if you or any member of your family has a history of blood clots or any known hereditary condition that increases the risk of forming these clots.
• In case you are admitted to a hospital, inform the healthcare staff that you are taking tamoxifeno.
• In a delayed breast reconstruction surgery (weeks or years after the primary breast surgery, when your own tissue is moved to shape a new breast), tamoxifeno may increase the risk of blood clots in small blood vessels of the tissue graft, which may lead to complications.
• This medication contains tamoxifeno, which may produce a positive result in doping control tests.
• Severe skin reactions, including Stevens-Johnson syndrome and toxic epidermal necrolysis, have been reported in association with tamoxifeno treatment. If you notice any symptoms related to these severe skin reactions described in section 4, stop using tamoxifeno and seek medical attention immediately.
• If you have a history of hereditary angioedema, as tamoxifeno may provoke or worsen angioedema symptoms. If you experience symptoms such as facial swelling, lips, tongue, and/or throat with difficulty swallowing or breathing, contact a doctor immediately.

Children and adolescents

Tamoxifeno should not be administered to children/adolescents, as its safety and efficacy have not been established in this age group.

Taking Tamoxifeno Viatris with other medications

Inform your doctor or pharmacist if you are taking, have taken recently, or may need to take any other medication.

You should never take another medication on your own initiative without your doctor's recommendation, as some combinations should be avoided.

In particular, you should inform your doctor if you are taking any of the following medications:

• Warfarina (an oral anticoagulant to prevent blood clots).
• Rifampicina (for tuberculosis).
• Aromatase inhibitors such as anastrozol, letrozol, or exemestano (used to treat breast cancer).
• Paroxetina, fluoxetina (antidepressants).
• Bupropión (antidepressant or used to quit smoking).
• Quinidina (used in the treatment of cardiac arrhythmia).
• Cinacalcet (for the treatment of parathyroid gland disorders).

Pregnancy, breastfeeding, and fertility

If you are pregnant or breastfeeding, think you may be pregnant, or intend to become pregnant, consult your doctor or pharmacist before using this medication.

Men or women should use an effective contraceptive method during tamoxifeno treatment, and women should continue for at least 7 months and men for at least 4 months after treatment is completed.

You should not be pregnant during tamoxifeno treatment or within two months after stopping treatment.

Do not take tamoxifeno if you are breastfeeding, unless your doctor has analyzed the risks and benefits involved. It is not known if tamoxifeno passes into breast milk.

Driving and operating machinery

The influence of tamoxifeno on the ability to drive and operate machinery is small.

However, fatigue has been reported with tamoxifeno use, so caution should be exercised when driving or operating machinery while these symptoms persist.

Tamoxifeno Viatris contains lactose, yellow orange S (E-110), and sodium

This medication contains lactose. If your doctor has indicated that you have an intolerance to certain sugars, consult with them before taking this medication.

This medication may cause allergic reactions because it contains yellow orange S (E-110). It may provoke asthma, especially in patients allergic to acetylsalicylic acid.

This medication contains less than 23 mg of sodium (1mmol) per tablet; it is essentially “sodium-free”.

Follow exactly the administration instructions for this medication as indicated by your doctor or pharmacist. In case of doubt, consult your doctor or pharmacist again.

Tamoxifeno Viatris Dosage

• The recommended dose is 1 tablet (20 mg) to 2 tablets (40 mg) per day.
• Tamoxifeno is usually taken once or twice a day.
• Swallow the tablets whole with water.
• Try to take the tablet at the same time every day.

Do not stop taking your tablets even if you feel well, unless your doctor tells you to.

Use in Children and Adolescents

Tamoxifeno should not be administered to children/adolescents, as its safety and efficacy have not been established in this age group.

If You Take More Tamoxifeno Viatris Than You Should

In case of overdose or accidental ingestion, consult your doctor or pharmacist immediately or call the Toxicological Information Service, phone 91 562 04 20, indicating the medication and the amount ingested, or go to the nearest hospital emergency department.

If You Forget to TakeTamoxifeno Viatris

If you forget a dose, take it as soon as you remember. Do not take a double dose to make up for the missed dose.

If You Interrupt Treatment with Tamoxifeno Viatris

Your doctor will indicate the duration of your treatment with tamoxifeno. Do not stop treatment before your doctor tells you to.

If you have any other questions about the use of this medication, ask your doctor or pharmacist.

Like all medications, this medication may cause side effects, although not everyone will experience them.

Stop taking tamoxifen and inform your doctor immediately if you notice any of the following symptoms or side effects, as you may need urgent medical treatment:

• Flat red spots, in the shape of a bull's-eye or circles on the trunk, often with central blisters, skin peeling, mouth ulcers, throat, nose, genital, and eye ulcers. These severe skin rashes may be preceded by fever and flu-like symptoms (Stevens-Johnson syndrome, toxic epidermal necrolysis); these side effects occur rarely.
• Swelling of the face, lips, tongue, or throat, difficulty swallowing or breathing (angioedema). Tamoxifen may cause or worsen symptoms of hereditary angioedema.

Very common (may affect more than 1 in 10 patients):

• Metabolic and nutritional disorders: Fluid retention.
• Vascular disorders: Hot flashes.
• Gastrointestinal disorders: Nausea.
• Skin and subcutaneous tissue disorders: Rash.
• Reproductive and breast disorders: Vaginal bleeding, vaginal discharge.
• General and local reactions: Fatigue.

Common (may affect up to 1 in 10 patients):

• Benign, malignant, and unspecified neoplasms (including cysts and polyps): Uterine fibroids.
• Blood and lymphatic system disorders: Decreased red blood cell count (anemia).
• Immune system disorders: Hypersensitivity reactions (allergic reactions).
• Nervous system disorders: Sudden weakness or paralysis of the arms or legs, sudden difficulty speaking, walking, holding things, or thinking (any of these may occur due to decreased blood flow to the brain and may be a sign of a stroke), headache, dizziness, sensory disturbances (including taste disturbances and numbness or tingling of the skin).
• Eye disorders: Cataracts, changes in the retina.
• Gastrointestinal disorders: Vomiting, diarrhea, constipation.
• Hepatobiliary disorders: Changes in liver enzymes, fatty liver accumulation.
• Skin and subcutaneous tissue disorders: Hair loss.
• Musculoskeletal and connective tissue disorders: Leg cramps, muscle pain.
• Reproductive and breast disorders: Vaginal itching, endometrial changes (interior of the uterus).
• Complementary examinations: Increased blood lipid levels.
• Disorders affecting multiple organs or systems: Increased risk of blood clots (including small vessel clots).

Uncommon (may affect up to 1 in 100 patients):

• Benign, malignant, and unspecified neoplasms (including cysts and polyps): Endometrial tumor (interior of the uterus).
• Blood and lymphatic system disorders: Decreased platelet count (thrombocytopenia), decreased white blood cell count (leukopenia).
• Metabolic and nutritional disorders: Elevated calcium levels in the blood (in patients with bone metastases).
• Eye disorders: Visual disturbances.
• Respiratory, thoracic, and mediastinal disorders: Inflammation of the lung area, which may present with symptoms similar to pneumonia, such as difficulty breathing and coughing.
• Gastrointestinal disorders: Pancreatitis (pain or tenderness in the upper abdomen).
• Hepatobiliary disorders: Liver cirrhosis (symptoms may include general discomfort, with or without yellowing of the skin and eyes), which in some cases has resulted in death.

Rare (may affect up to 1 in 1,000 patients):

• Benign, malignant, and unspecified neoplasms (including cysts and polyps): Uterine tumor (matrix), symptoms related to your disease.
• Blood and lymphatic system disorders: Decreased neutrophil count (neutropenia), isolated decrease in levels of a specific type of white blood cell (agranulocytosis).
• Nervous system disorders: Optic nerve inflammation and in a small number of cases, loss of vision (caused by optic nerve inflammation).
• Eye disorders: Changes in the cornea, optic nerve alterations, and in a small number of cases, loss of vision (caused by optic nerve alteration).
• Hepatobiliary disorders: Hepatitis, bile duct obstruction, liver failure, liver cell damage (symptoms may include general discomfort, with or without yellowing of the skin and eyes), which in some cases has resulted in death.
• Skin and subcutaneous tissue disorders: Angioedema (swelling of the face, lips, tongue, and/or throat), inflammation of small blood vessels in the skin that triggers a skin rash, severe skin reactions, with lesions, ulcers, or vesicles.
• Reproductive and breast disorders: Uterine tissue disorders, ovarian cysts, vaginal polyps (non-tumorous mass in the vagina).

Very rare (may affect up to 1 in 10,000 patients):

• Skin and subcutaneous tissue disorders: Cutaneous lupus erythematosus (skin inflammation characterized by a rash or redness, especially in exposed areas).
• Congenital, familial, and genetic disorders: Skin condition characterized by the presence of blisters due to elevated production of a specific group of pigments (called porphyrins) by the liver.

If you experience symptoms of blood clot formation such as swelling in the calf or leg, chest pain, feeling of shortness of breath, or sudden weakness. STOP ADMINISTERING tamoxifen and contact your doctor immediately.

Reporting of side effects

If you experience any type of side effect, consult your doctor or pharmacist, even if it is a possible side effect that does not appear in this leaflet. You can also report them directly through the Spanish System for the Vigilance of Medicinal Products for Human Use: https://www.notificaram.es. By reporting side effects, you can contribute to providing more information on the safety of this medication.

Keep this medication out of the sight and reach of children.

Do not use this medication after the expiration date that appears on the packaging after CAD or EXP. The expiration date is the last day of the month indicated.

Store in the original packaging to protect it from light.

Medications should not be disposed of through drains or in the trash. Dispose of the packaging and medications you no longer need at the SIGRE collection point of the pharmacy. If in doubt, ask your pharmacist how to dispose of the packaging and medications you no longer need. By doing so, you will help protect the environment.

Tamoxifeno Viatris Composition

• The active ingredient is tamoxifen (as citrate). Each tablet contains 30.34 mg of tamoxifen citrate equivalent to 20.0 mg of tamoxifen.
• The other components are: cornstarch, lactose, povidone (E-1201), yellow-orange S (E-110), sodium croscarmellose (E-468), magnesium stearate (E-470b), colloidal silica, talc (E-553b), and hypromellose (E-464).

Product appearance and container content

The film-coated tablets are orange, round, biconvex, and engraved with “20” on the upper and smooth lower face.

Tamoxifeno Viatris is presented in containers of 30 and 60 film-coated tablets conditioned in blisters.

Only some container sizes may be commercially marketed.

Marketing Authorization Holder

Viatris Pharmaceuticals, S.L.U.

C/ General Aranaz, 86

28027 - Madrid

Spain

Responsible for Manufacturing

Prasfarma, S.L.

C/ Sant Joan, 11-15

08560 - Manlleu, Barcelona

Spain

Last review date of this leaflet:August 2024

The detailed information of this medicine is available on the website of the Spanish Agency for Medicines and Medical Devices (AEMPS) https://www.aemps.gob.es/