Tamoxifen is the oldest and most-prescribed selective estrogen receptor modulator (SERM). Tamoxifen is approved by the U.S. Food and Drug Administration (FDA) to treat: women and men diagnosed with hormone-receptor-positive, early-stage breast cancer after surgery (or possibly chemotherapy and radiation) to reduce the risk of the cancer coming back (recurring), women and men diagnosed with advanced-stage or metastatic hormone-receptor-positive disease Tamoxifen also is used to: reduce breast cancer risk in women who haven't been diagnosed but are at higher-than-average risk for the disease Tamoxifen won't work on hormone-receptor-negative breast cancer. Tamoxifen is available in two forms: a pill taken once a day (brand name: Nolvadex) or a liquid form (brand name: Soltamox). If you dislike pills or you're having trouble swallowing tamoxifen pills, Soltamox can help make it easier to stay on your treatment plan. Most doctors recommend taking tamoxifen at the same time each day. You should not take tamoxifen if you are breastfeeding, pregnant, trying to get pregnant, or if there is any chance that you could be pregnant. Tamoxifen may cause damage to developing embryos. You should use an effective non-hormonal type of birth control — such as condoms, a diaphragm along with spermicide, or a non-hormonal I.U.D. — while you are taking tamoxifen and for 2 months afterward. Ask your doctor which type of non-hormonal birth control would be best for you.
Tamoxifen is used to treat breast cancer. It is also used to reduce the chances of breast cancer in high-risk patients. This medication can block the growth of breast cancer. It works by interfering with the effects of estrogen in the breast tissue. How to use Tamoxifen CITRATE Read the Medication Guide provided by your pharmacist before you start using tamoxifen and each time you get a refill. If you have any questions, consult your doctor or pharmacist. Take this medication by mouth with or without food, usually once or twice daily for 5 years. Daily dosages greater than 20 milligrams are usually divided in half and taken twice a day, in the morning and evening. If you are using the liquid, measure the dose carefully using a special measuring device/spoon. Do not use a household spoon because you may not get the correct dose. Dosage is based on your medical condition and response to treatment. The duration of treatment to prevent cancer from returning may be between 5 to 10 years, depending on your medical condition and response to treatment. Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time(s) each day. If you have breast cancer that has spread to other parts of the body, you may experience increased bone/cancer pain and/or disease flare-up as you start taking tamoxifen. In some cases, this may be a sign of a good response to the medication. Symptoms include increased bone pain, increased tumor size, or even new tumors. These symptoms usually disappear quickly. In any case, report these symptoms right away to your doctor. Since this drug can be absorbed through the skin and lungs, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets. (See also Precautions section.)
Before taking tamoxifen, tell your doctor or pharmacist if you are allergic to it; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details. Before using this medication, tell your doctor or pharmacist your medical history, especially of: blood clots (e.g., deep vein thrombosis, pulmonary embolism, stroke), high cholesterol/triglycerides, limited or no ability to walk (immobility), diabetes, high blood pressure, smoking, cataracts, liver disease. Before having surgery (especially breast reconstruction), tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products). Tell your doctor if you are pregnant or plan to become pregnant. You should not become pregnant while using tamoxifen. Tamoxifen may harm an unborn baby. Women using this medication should ask about reliable non-hormonal forms of birth control (such as condoms, diaphragms with spermicide) during treatment and for 2 months after stopping treatment. Men using this medication should ask about reliable forms of birth control during treatment and for 6 months after stopping treatment. If you or your partner become pregnant, talk to your doctor right away about the risks and benefits of this medication. It is unknown if this medication passes into breast milk. Because of the possible risk to the infant, breast-feeding is not recommended while using this drug and for 3 months after stopping treatment. Consult your doctor before breast-feeding.
Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval. Some products that may interact with this drug are: anastrozole, "blood thinners" (e.g., warfarin), estrogens, letrozole, hormonal forms of birth control (e.g., birth control pills, patches, implants), ribociclib. Other medications can affect the removal of tamoxifen from your body, which may affect how tamoxifen works. Examples include cimetidine, rifamycins (e.g., rifampin), SSRI antidepressants (e.g., fluoxetine, paroxetine), St. John's wort, drugs used to treat seizures (e.g., carbamazepine, phenobarbital, phenytoin, primidone), among others. This medication may interfere with certain laboratory tests (including thyroid tests), possibly causing false test results. Make sure laboratory personnel and all your doctors know you use this drug.