1. What is Tamoxifen and what is it used for?
Tamoxifen belongs to the group of antiestrogens. That is, they counteract the effects of estrogens, the female sex hormones.
Certain tumors develop under the influence of estrogens. Tamoxifen may inhibit or prevent the development of these tumors.
Tamoxifen is sometimes used to treat breast cancer.
2. What do you need to know before using Tamoxifen ?
Tamoxifen must not be used:
If you are hypersensitive (allergic) to any of the ingredients of Tamoxifen . The ingredients can be found under point 6.
If you are pregnant, plan to become pregnant or breastfeed. You must consult your doctor immediately if you think you may have become pregnant while taking Tamoxifen .
Take special care with Tamoxifen
If unusual vaginal blood loss or other gynecological symptoms (such as abdominal pain or pressure) occur when you are taking Tamoxifen or even after discontinuing treatment. You must report this to your doctor immediately.
If you start to experience unusual nausea, vomiting and thirst. This may indicate a possible change in the amount of calcium in the blood, and it may be necessary for your doctor to perform certain blood tests.
If you already belong to the risk group for uterine cancer. The risk of developing uterine cancer is increased by the use of tamoxifen.
3. When using Tamoxifen with other medicines
Please tell your doctor or pharmacist if you are taking or have recently taken any other medicines, even those not prescribed. This may be relevant in, for example, blood thinners. Co-administration of tamoxifen with these medicinal products may increase the anticoagulant effect.
Using Tamoxifen with food and drink
pregnancy and breast feeding period
Ask your doctor or pharmacist for advice before taking any medicine.
Observations in experimental animals indicate that tamoxifen has a damaging effect on the fetus. Tamoxifen should not be given during pregnancy. There are no data available on whether tamoxifen passes into breast milk. Therefore, the use of tamoxifen during breast-feeding must be avoided.
Tamoxifen should not be taken during pregnancy. Some cases of spontaneous miscarriage, birth complications and stillbirth in women treated with tamoxifen have been reported, although no causal relationship has been established.
Driving and using machines
Tamoxifen has little or no influence on the ability to drive a vehicle and operate machinery.
Important information about some of the ingredients of Tamoxifen
This medicine contains lactose. Please take Tamoxifen only after consultation with your doctor, if you are aware that you have a sugar intolerance.
4. What side effects are possible from tamoxifen?
Like all medicines, Tamoxifen can cause side effects, although not everybody gets them.
The evaluation of adverse reactions is based on the following frequency information:
Benign, malignant and nonspecific neoplasms (including cysts and polyps)
Common: transient increase in tumor growth (“tumor flare”)
Diseases of the blood and lymphatic system
Uncommon: abnormal blood counts: lack of platelets with bruising and bleeding (thrombocytopenia); Lack of white blood cells associated with increased susceptibility to infections (leukopenia and neutropenia) and anemia (anemia).
Immune system disorders
Uncommon: Hypersensitivity reactions, including sudden fluid accumulation of the skin and mucous membranes (eg on the throat or tongue), accompanied by difficulty in breathing and / or itching and rash (Quincke’s edema).
Metabolic and nutritional disorders
Common: Water retention Rare: elevated blood calcium level (hypercalcemia)
Unknown: severe depression over a long period of time (depression)
Diseases of the nervous system
Common: headache and dizziness (feeling light-headed)
Uncommon: decreased vision due to eye lens (cataract) and / or retina (retinopathy) Rare: decreased vision due to changes in the cornea and some visual disturbances.
Very common: hot flashes Common: formation of blood clots (thromboembolic complications), i.a. Thrombosis of blood vessels and lungs (pulmonary embolism). When Tamoxifen is used in combination with chemotherapy, there is an increased risk of developing thromboembolic complications.
Respiratory, thoracic and mediastinal disorders
Very rare: connective tissue inflammation of a pulmonary lobe part (interstitial pneumonia)
Common: Tendency to digestive disorders such. Nausea and / or vomiting (gastrointestinal intolerance) Rare: inflammation of the pancreas accompanied by severe upper abdominal pain radiating to the back and nausea (pancreatitis)
Liver and biliary disorders
Rare: fatty liver, biliary stasis (cholestasis), hepatitis accompanied by jaundice (yellowing of skin and eyes)
Skin and subcutaneous tissue disorders
Very common: sweating increasingly Common: Hair loss, rash / rash Very rare: rash with red irregular patches (erythema multiforme); severe hypersensitivity reaction with (high) fever, red spots on the skin, joint pain and / or eye inflammation (Stevens-Johnson syndrome) and blisters with whitish-yellowish fluid (skin disease: bullous pemphigoid)
Musculoskeletal, Connective Tissue and Bone Diseases
Not known: mild joint pain (arthralgia) including joint inflammation (arthritis)
Diseases of the sexual organs and the mammary gland
Very common: irregular menstruation Common: absence of menstruation, vaginal blood loss, vaginal discharge, itching of the labia (pruritus vulvae), change in the lining of the uterus, u.a. excessive mucous membrane (hyperplasia) and benign stalk-shaped mucous membrane (polyps) Uncommon: tumor on muscle and connective tissue (fibromyomas) of the uterus, uterine cancer Rare: proliferation of the uterine lining (endometriosis), tumor on the uterus (ovarian cyst), malignant growth on the uterus ( Sarcomas of the uterus, mostly malignant Müller mixed tumors).
General disorders and administration site conditions
Not known: tiredness
Common: increased amount of fatty substances (triglycerides) in the blood
Itching, rash, swelling of a blood vessel as a result of an allergic reaction (referred to as Quincke’s edema), nettle rash, bronchospasm and very rarely severe hypersensitivity reaction with (high) fever, red spots on the skin, joint pain and / or ophthalmia (as Stevens-Johnson Syndrome).
If these side effects are severe, it may occasionally be possible to reduce them by reducing the dose (within the recommended interval) while maintaining the drug’s effect. If the side effects do not disappear after a dose reduction, treatment may be discontinued.
If any of the side effects gets serious, or if you notice any side effects not listed in this leaflet, please tell your doctor or pharmacist.
5. How to store Tamoxifen?
Store at room temperature (15 – 25 ° C).