TAMOXIFEN CITRATE- tamoxifen citrate tablet
Tamoxifen Citrate Tablets, USP
Written for women who use tamoxifen to lower their high chance of getting breast cancer or who have ductal carcinoma in situ (DCIS)
This Medication Guide discusses only the use of tamoxifen to lower the chance of getting breast cancer in high-risk women and in women treated for DCIS.
People taking tamoxifen to treat breast cancer have different benefits and different decisions to make than high-risk women or women with ductal carcinoma in situ (DCIS) taking tamoxifen to reduce the chance of getting breast cancer. If you already have breast cancer, talk with your doctor about how the benefits of treating breast cancer with tamoxifen compare to the risks that are described in this document.
Why should I read this Medication Guide?
This guide has information to help you decide whether to use tamoxifen to lower your chance of getting breast cancer.
You and your doctor should talk about whether the possible benefit of tamoxifen in lowering your high chance of getting breast cancer is greater than its possible risks. Your doctor has a special computer program or hand-held calculator to tell if you are in the high-risk group. If you have DCIS and have been treated with surgery and radiation therapy, your doctor may prescribe tamoxifen to decrease your chance of getting invasive (spreading) breast cancer.
Read this guide carefully before you start tamoxifen. It is important to read the information you get each time you get more medicine. There may be something new. This guide does not tell you everything about tamoxifen and does not take the place of talking with your doctor.
Only you and your doctor can determine if tamoxifen is right for you.
What is the most important information I should know about using tamoxifen to reduce the chance of getting breast cancer?
Tamoxifen is a prescription medicine that is like estrogen (female hormone) in some ways and different in other ways. In the breast, tamoxifen can block estrogen’s effects. Because it does this, tamoxifen may block the growth of breast cancers that need estrogen to grow (cancers that are estrogen- or progesterone-receptor positive).
Tamoxifen can lower the chance of getting breast cancer in women with a higher than normal chance of getting breast cancer in the next five years (high-risk women) and women with DCIS.
Because high-risk women don’t have cancer yet, it is important to think carefully about whether the possible benefit of tamoxifen in lowering the chance of getting breast cancer is greater than its possible risks.
This Medication Guide reviews the risks and benefits of using tamoxifen to reduce the chance of getting breast cancer in high-risk women and women with DCIS. This guide does not discuss the special benefits and decisions for people who already have breast cancer.
Why do women and men use tamoxifen?
Tamoxifen has more than one use. Tamoxifen is used:
This guide talks only about using tamoxifen to lower the chance of getting breast cancer (#1 and #2 above).
What are the benefits of tamoxifen to lower the chance of getting breast cancer in high-risk women and in women treated for DCIS?
A large U.S. study looked at high-risk women and compared the ones who took tamoxifen for 5 years with others who took a pill without tamoxifen (placebo). High-risk women were defined as women who have a 1.7% or greater chance of getting breast cancer in the next 5 years, based on a special computer program. In this study:
The study showed that on average, high-risk women who took tamoxifen lowered their chances of getting breast cancer by 44%, from 7 in 1000 to 4 in 1000.
Another U.S. study looked at women with DCIS and compared those who took tamoxifen for 5 years with others who took a placebo. In this study:
The study showed that on average, women with DCIS who took tamoxifen lowered their chances of getting invasive (spreading) breast cancer by 43%, from 17 in 1000 to 10 in 1000.
These studies do not mean that taking tamoxifen will lower your personal chance of getting breast cancer. We do not know what the benefits will be for any one woman who takes tamoxifen citrate to reduce her chance of getting breast cancer.
What are the risks of tamoxifen?
In the studies described under “ What are the benefits of tamoxifen?”, the high-risk women who took tamoxifen citrate got certain side effects at a higher rate than those who took a placebo. Some of these side effects can cause death.
In one study, in women who still had their uterus:
These results show that, on average, in high-risk women who still had their uterus, tamoxifen citrate doubled the chance of getting endometrial cancer from 1 in 1000 to 2 in 1000, and it increased the chance of getting uterine sarcoma. This does not mean that taking tamoxifen will double your personal chance of getting endometrial cancer or increase your chance of getting uterine sarcoma. We do not know what this risk will be for any one woman. The risk is different for women who no longer have their uterus.
For all women in this study, taking tamoxifen increased the risk of having a blood clot in their lungs or veins, or of having a stroke. In some cases, women died from these effects.
Tamoxifen increased the risk of getting cataracts (clouding of the lens of the eye) or needing cataract surgery. (See “ What are the possible side effects of tamoxifen?” for more details about side effects.)
What don’t we know about taking tamoxifen citrate to reduce the chance of getting breast cancer?
We don’t know:
Studies are being done to learn more about the long-term benefits and risks of using tamoxifen to reduce the chance of getting breast cancer.
What are the possible side effects of tamoxifen?
The most common side effect of tamoxifen is hot flashes. This is not a sign of a serious problem.
The next most common side effect is vaginal discharge. If the discharge is bloody, it could be a sign of a serious problem. [See “ Changes in the lining (endometrium) or body of your uterus” below.]
Less common but serious side effects of tamoxifen are listed below. These can occur at any time. Call your doctor right away if you have any signs of side effects listed below:
- Vaginal bleeding or bloody discharge that could be a rusty or brown color. You should call your doctor even if only a small amount of bleeding occurs.
- Change in your monthly bleeding, such as in the amount or timing of bleeding or increased clotting.
- Pain or pressure in your pelvis (below your belly button).
- sudden chest pain, shortness of breath, coughing up blood
- pain, tenderness, or swelling in one or both of your legs
- sudden weakness, tingling, or numbness in your face, arm or leg, especially on one side of your body
- sudden confusion, trouble speaking or understanding
- sudden trouble seeing in one or both eyes
- sudden trouble walking, dizziness, loss of balance or coordination
- sudden severe headache with no known cause
These are not all the possible side effects of tamoxifen. For a complete list, ask your doctor or pharmacist.
Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.
Who should not take tamoxifen?
Do not take tamoxifen for any reason if you
If you get pregnant while taking tamoxifen, stop taking it right away and contact your doctor. Tamoxifen may harm your unborn baby.
Do not take tamoxifen to lower your chance of getting breast cancer if:
How should I take tamoxifen?
What should I avoid while taking tamoxifen?
What should I do while taking tamoxifen?
General information about the safe and effective use of tamoxifen.
Medicines are sometimes prescribed for purposes other than those listed in a Medication Guide. Your doctor has prescribed tamoxifen only for you. Do not give it to other people, even if they have a similar condition, because it may harm them. Do not use it for a condition for which it was not prescribed.
This Medication Guide is a summary of information about tamoxifen for women who use tamoxifen to lower their high chance of getting breast cancer or who have DCIS. If you want more information about tamoxifen, ask your doctor or pharmacist. They can give you information about tamoxifen that is written for health professionals. For more information about tamoxifen or breast cancer, call 1-800-272-5525.
Ingredients: tamoxifen citrate, croscarmellose sodium, lactose monohydrate, magnesium stearate, microcrystalline cellulose, and pregelatinized starch.
*Coumadin® is a registered trademark of Bristol-Myers Squibb Pharmaceuticals.
This Medication Guide has been approved by the U.S. Food and Drug Administration.
Actavis Laboratories FL, Inc.
Fort Lauderdale, FL 33314 USA
Actavis Pharma, Inc.
Parsippany, NJ 07054 USA
Revised: April 2015