TAMOXIFEN (ta MOX i fen) blocks the effects of estrogen. It is commonly used to treat breast cancer. It is also used to decrease the chance of breast cancer coming back in women who have received treatment for the disease. It may also help prevent breast cancer in women who have a high risk of developing breast cancer.
Take this medicine by mouth with a glass of water. Follow the directions on the prescription label. You can take it with or without food. Take your medicine at regular intervals. Do not take your medicine more often than directed. Do not stop taking except on your doctor's advice.
A special MedGuide will be given to you by the pharmacist with each prescription and refill. Be sure to read this information carefully each time.
Talk to your pediatrician regarding the use of this medicine in children. While this drug may be prescribed for selected conditions, precautions do apply.
Side effects that you should report to your doctor or health care professional as soon as possible:
allergic reactions like skin rash, itching or hives, swelling of the face, lips, or tongue
changes in vision
changes in your menstrual cycle
difficulty walking or talking
new breast lumps
pelvic pain or pressure
redness, blistering, peeling or loosening of the skin, including inside the mouth
signs and symptoms of a dangerous change in heartbeat or heart rhythm like chest pain, dizziness, fast or irregular heartbeat, palpitations, feeling faint or lightheaded, falls, breathing problems
sudden chest pain
swelling, pain or tenderness in your calf or leg
unusual bruising or bleeding
vaginal discharge that is bloody, brown, or rust
yellowing of the whites of the eyes or skin
Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):
hair loss, although uncommon and is usually mild
impotence (in men)
nausea, vomiting (mild)
vaginal discharge (white or clear)
Do not take this medicine with any of the following medications:
certain medicines for irregular heart beat like dofetilide, dronedarone, quinidine
certain medicines for fungal infection like fluconazole, posaconazole
This medicine may also interact with the following medications:
female hormones, like estrogens and birth control pills
If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.
Keep out of the reach of children.
Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Protect from light. Keep container tightly closed. Throw away any unused medicine after the expiration date.
They need to know if you have any of these conditions:
cataracts or impaired eyesight
high calcium levels
irregular menstrual cycles
an unusual reaction to tamoxifen, other medicines, foods, dyes, or preservatives
pregnant or trying to get pregnant
Visit your doctor or health care professional for regular checks on your progress. You will need regular pelvic exams, breast exams, and mammograms. If you are taking this medicine to reduce your risk of getting breast cancer, you should know that this medicine does not prevent all types of breast cancer. If breast cancer or other problems occur, there is no guarantee that it will be found at an early stage.
Do not become pregnant while taking this medicine or for 2 months after stopping it. Women should inform their doctor if they wish to become pregnant or think they might be pregnant. There is a potential for serious side effects to an unborn child. Talk to your health care professional or pharmacist for more information. Do not breast-feed an infant while taking this medicine or for 3 months after stopping it.
This medicine may interfere with the ability to have a child. Talk with your doctor or health care professional if you are concerned about your fertility.