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Tamoxifen citrate oral

Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.




WARNING: Tamoxifen rarely may cause serious (possibly fatal) side effects. These include cancer of the uterus (endometrial cancer and uterine sarcoma), as well as strokes and blood clots in the lung (pulmonary emboli). Tell your doctor immediately if you develop: abnormal vaginal bleeding, irregular or abnormal menstrual periods, groin pain or pressure, chest pain, trouble breathing, one-sided weakness. If you are taking this medication for prevention of breast cancer (those with ductal carcinoma in situ-DCIS, or those at high risk for breast cancer) you should discuss with your doctor the risks of treatment as compared to the benefits. However, if you are taking tamoxifen for treatment of breast cancer, the proven benefits clearly are greater than the risk of side effects. Consult your doctor or pharmacist for more details.


Tamoxifen is a drug that blocks the action of the hormone estrogen. It is used in the treatment and prevention of breast cancer in women.



This medication may also be used short-term (less than one year) to treat girls age 2 -10 years of age who have premature puberty (McCune-Albright Syndrome).

How To Use

Take this drug by mouth exactly as prescribed for the full treatment period. Read the Medication Guide provided by your pharmacist. Consult your doctor or pharmacist if you have any questions.

Side Effects

Nausea, hot flashes, weight gain or headache may occur. If these effects persist or worsen, notify your doctor promptly. Report promptly: abnormal vaginal bleeding or irregular periods, vaginal discharge, groin pain, vision changes. Unlikely but report promptly: vomiting, rash. Tell your doctor immediately if any of these highly unlikely but very serious side effects occur: dark urine, yellowing eyes and skin, easy bruising, persistent sore throat, fever, mental or mood changes, trouble breathing, unusual tiredness, leg pain or swelling, dizziness. If you notice other effects not listed above, contact your doctor or pharmacist.


Tell your doctor your medical history, especially of: eye problems, blood disorders, cancers, liver disease, allergies (especially drug allergies). Use reliable birth control (e.g., proven barrier methods) during treatment and for at least two months after treatment. Consult your doctor or pharmacist. This drug is not recommended for use during pregnancy. Consult your doctor before using this drug. It is not known if this drug is excreted into breast milk. Because of the potential risk to the infant, breast-feeding while using this drug is not recommended. Consult your doctor before breast-feeding.

Drug Interactions

This drug is not recommended for use with mibefradil or letrozole. Ask your doctor or pharmacist for more details. Tell your doctor or pharmacist of all prescription and nonprescription drugs you may use, especially of: warfarin, rifampin, St. John's wort. Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately. Symptoms of overdose may include shakiness, dizziness, fainting, and irregular heartbeat.


Keep all doctor and lab visits (e.g., yearly pelvic/gynecology exams) because it is important to have your progress monitored.

Missed Dose

If you miss a dose, take as soon as remembered; do not take if it is almost time for the next dose, instead, skip the missed dose and resume your usual dosing schedule. Do not "double-up" the dose to catch up.


Store at room temperature away from sunlight and moisture.

Medical Alert

Your condition can cause complications in a medical emergency. For enrollment information call MedicAlert at 1-800-854-1166 (USA), or 1-800-668-1507 (Canada).