What is tamoxifen
blocks the actions of the hormone estrogen. Certain types
of breast cancer require estrogen to grow.
is used to treat and prevent some types of breast cancer that
require estrogen to grow.
may also be used for purposes other than those listed in this
General medical information about tamoxifen
Treatment with tamoxifen may increase the risk of
certain uterine cancers, stroke, and pulmonary embolism
(blood clot in the lung), which may be fatal. You should
discuss with your doctor the risks and benefits associated
with the use of tamoxifen.
What you should find out before taking
Before taking tamoxifen, tell your doctor if you
- have a history of deep vein thrombosis (blood clot
in the leg);
- have a history of pulmonary thrombosis
(blood clot in the lung); or
- take the blood thinner
You may not be able to take
tamoxifen, or you may require a dosage adjustment or special
monitoring during treatment.
Tamoxifen is in the
FDA pregnancy category D. This means that tamoxifen is known
to be harmful to an unborn baby. Do not take tamoxifen without
first talking to your doctor if you are pregnant or could
become pregnant during or for two months following treatment.
Effective nonhormonal contraception (birth control) should
be used during and for two months following treatment with
It is not known whether tamoxifen passes
into breast milk. Do not take tamoxifen without first talking
to your doctor if you are breast-feeding a baby.
How should take tamoxifen Take tamoxifen exactly as directed by your doctor.
If you do not understand these directions, ask your pharmacist,
nurse, or doctor to explain them to you.
dose with a full glass (8 ounces) of water.
can be taken with or without food.
It is important
to take tamoxifen regularly to get the most benefit.
Your doctor may want you to have breast exams (or to perform
self breast exams), mammograms, blood tests, or other medical
evaluations during treatment with tamoxifen to monitor progress
and side effects.
Store tamoxifen at room temperature
away from moisture and heat.
If you miss a dose: Take the missed dose as soon as you remember. However,
if it is almost time for the next dose, skip the missed
dose and take only the next regularly scheduled dose. Do
not take a double dose of this medication unless your doctor
What happens if you overdose: An overdose of tamoxifen is unlikely to threaten
life. Call an emergency room or a poison control center
for advice if you suspect an overdose.
a tamoxifen overdose are unknown, but nausea, vomiting,
seizures, tremor, or dizziness may be expected.
Avoid while taking tamoxifen There are no restrictions on food, beverages, or
activity during treatment with tamoxifen unless otherwise
directed by your doctor.
Possible side effects of tamoxifen Stop taking tamoxifen and seek emergency medical
attention or contact your doctor immediately if you experience
any of the following serious side effects:
- an allergic
reaction (difficulty breathing; closing of the throat; swelling
of the lips, tongue, or face; or hives);
symptoms of a stroke such as unusual weakness, drowsiness,
confusion, or difficulty walking or talking;
symptoms of a blood clot in the lung such as chest pain,
shortness of breath, or coughing up blood;
symptoms of a blood clot in the brain or leg such as blurred
vision, changes in vision, numbness, or pain or swelling
in a leg;
- new breast lumps;
- bone pain;
- menstrual changes, abnormal vaginal bleeding, vaginal
discharge, or pelvic pain or pressure;
- pain or
tenderness in the upper abdomen;
- yellowing of the
skin or eyes; or
- excessive nausea, vomiting, or
Other, less serious side effects may be more
likely to occur. Continue to take tamoxifen and talk to
your doctor if you experience
- dizziness or headache;
- mild nausea, vomiting, or decreased appetite;
- hot flashes; or
Treatment with tamoxifen may increase
the risk of certain uterine cancers, stroke, and pulmonary
embolism (blood clot in the lung), which may be fatal. You
should discuss with your doctor the risks and benefits associated
with the use of tamoxifen.
Side effects other than
those listed here may also occur. Talk to your doctor about
any side effect that seems unusual or that is especially
What other drugs will affect tamoxifen Before taking tamoxifen, tell your doctor if you
- an estrogen such as Premarin, Ogen,
Estratest, Estraderm, Vivelle, Climara, and others;
a birth control pill that contains estrogen;
(Coumadin) or another blood thinner; or
You may not be able to take tamoxifen
or you may require special monitoring or a dosage adjustment
if you are taking any of the medicines listed above.
other than those listed here may also interact with tamoxifen.
Talk to your doctor and pharmacist before taking any prescription
or over-the-counter medicines, including herbal products.