Tamoxifen is a drug to treat breast cancer. This drug is also used to reduce the risk of breast cancer in women who have a high risk, for example because of a family history of breast cancer.
Tamoxifen works by blocking the effects of estrogen on the breast. Some types of breast cancer require the hormone estrogen to develop. This method of action can be used in the treatment of breast cancer and the prevention of breast cancer in women who are at high risk.
In addition, tamoxifen can also stimulate ovulation, so it can be used in the treatment of infertility in women.
What is Tamoxifen
|Benefit||Treat and reduce the risk of breast cancer|
|Tamoxifen for pregnant and lactating women||Category D:There is positive evidence of risks to the human fetus, but the benefits may outweigh the risks, for example in dealing with life-threatening situations. |
It is not known whether tamoxifen is absorbed into breast milk or not. If you are breastfeeding, do not use this medicine without telling your doctor.
|Drug form||Film-coated tablets|
Warnings Before Taking Tamoxifen
Follow the doctor's recommendations and advice while undergoing treatment with tamoxifen. Before taking this drug, you need to pay attention to the following:
- Tell your doctor about any allergies you have. Tamoxifen should not be used by someone who is allergic to this drug.
- Tell your doctor if you have or have had liver disease, blood clotting disorders, stroke, pulmonary embolism, deep vein thrombosis, high cholesterol, high triglycerides, diabetes, high blood pressure, or cataracts.
- Tell your doctor if you are temporarily sedentary or immobilized, are taking blood-thinning medication, or are in the habit of smoking.
- Tell your doctor if you are pregnant, breastfeeding, or planning a pregnancy. Tamoxifen should not be used by women who are pregnant. Consult the type of effective contraception with your doctor to prevent pregnancy.
- Tell your doctor that you are taking tamoxifen if you are going to have any surgery, including dental surgery.
- Consult a doctor if you or your family has a history of cancer, because tamoxifen can increase the risk of endometrial cancer, liver cancer, or uterine cancer.
- Tell your doctor if you have menstrual irregularities or have vaginal bleeding outside of your menstrual cycle.
- Tell your doctor if you are taking any medications, supplements, or herbal products.
- See your doctor right away if you have an allergic drug reaction, serious side effect, or overdose after taking tamoxifen.
Dosage and Rules for Use of Tamoxifen
The dose of tomoxifen prescribed by a doctor can be different for each patient. The following are tamoxifen dosages based on treatment goals:
Purpose: Treating breast cancer
- The dose is 20–40 mg per day. Doses above 20 mg are usually divided into 2 times a day
Purpose: Reducing the risk of breast cancer in high-risk women
- The dose is 20 mg per day, for 5 years.
Purpose: Overcoming infertility due to failure of ovulation in women with regular menstruation
- The initial dose is 20 mg per day, given on days 2–5 of the menstrual cycle. The dose may be increased to 40–80 mg per day in subsequent cycles.
Purpose: Overcoming infertility due to failure of ovulation in women with irregular menstruation
- The initial dose is 20 mg per day. If needed, the dose can be increased to 40-80 mg per day. If menstruation occurs, the next treatment is carried out on the 2nd day of the menstrual cycle.
How to Take Tamoxifen Correctly
Follow the doctor's advice and read the information listed on the drug packaging label before taking tamoxifen. Do not reduce or increase the dose without consulting your doctor first.
Tamoxifen can be taken before or after meals. Swallow the tablet whole with the help of a glass of water. Do not crush or chew the tablet.
Use tamoxifen regularly for maximum treatment. Do not stop using the drug without consulting your doctor first.
If you forget to take tamoxifen, it is advisable to take it immediately if the break with the next consumption schedule is not too close. If it is close, ignore it and do not double the dose.
Store tamoxifen at room temperature and avoid direct sunlight. Keep this medicine out of reach of children.
Tamoxifen Interactions with Other Drugs
The following are drug-drug interactions that may occur if tamoxifen is used together with other drugs:
- Increased risk of bleeding if used with blood-thinning medications, such as warfarin
- Increased risk of developing blood clots if used with other anticancer drugs, such as doxorubicin, daunorubicin, or vincristine
- Increased blood levels of tamoxifen when used with bromocriptine
- Decreased blood levels of tamoxifen when used with CYP3A4 inducers, such as rifampicin, or aminoglutethimide
- Decreased therapeutic effect of tamofixen when used with CYP2D6 inhibitors, such as paroxetine, fluoxetine, Cinacalcet, bupropion, or quinidine
- Decreased effectiveness of tamoxifen when used with birth control pills or hormone replacement therapy drugs
- Decreased blood levels of letrozole
Tamoxifen Side Effects and Dangers
Some of the side effects that can occur after using tamoxifen are:
- Nausea or stomach cramps
- Headache or dizziness
- Thin hair
- Loss of sexual desire, especially in men
- Too tired
- Weight loss
- Warmth in the face, neck, or chest (flush)
- Menstrual cycle disorders or vaginal discharge
Consult a doctor if the side effects above do not subside immediately or are actually getting worse. Immediately see a doctor if you experience an allergic drug reaction or more serious side effects, such as:
- Visual disturbances, such as blurred vision, tunnel vision, or eye pain
- The appearance of a new lump in the breast
- The appearance of bleeding outside the menstrual cycle or menstrual cycle disorders
- Liver disease that can be characterized by symptoms, such as jaundice, abdominal pain, excessive tiredness, or loss of appetite
- High levels of calcium in the blood which can be characterized by symptoms, such as constipation, muscle weakness, bone pain, feeling tired, confused, or weak
In addition, the use of tamoxifen can also increase the risk of blood clots that can block blood vessels and cause stroke or pulmonary embolism.