Barr - Tamoxifen Citrate

• 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.

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:

Changes in the lining (endometrium) or body of your uterus. These changes may mean serious problems are starting, including cancer of the uterus. The signs of changes in the uterus are:

• 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).

Blood clots in your veins or lungs. These can cause serious problems, including death. You may get clots up to 2-3 months after you stop taking tamoxifen. The signs of blood clots are:

• sudden chest pain, shortness of breath, coughing up blood
• pain, tenderness, or swelling in one or both of your legs

Stroke. Stroke can cause serious medical problems, including death. The signs of stroke are:

• 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

Cataracts or increased chance of needing cataract surgery. The sign of these problems is slow blurring of your vision.

Liver problems, including jaundice. The signs of liver problems include lack of appetite and yellowing of your skin or whites of your eyes.

Do not take tamoxifen for any reason if you:

• Are pregnant or plan to become pregnant while taking tamoxifen or during the 2 months after you stop taking tamoxifen. Tamoxifen may harm your unborn baby. It takes about 2 months to clear tamoxifen from your body. To be sure you are not pregnant, you can start taking tamoxifen while you are having your menstrual period. Or, you can take a pregnancy test to be sure you are not pregnant before you begin.
• Are breastfeeding. We do not know if tamoxifen can pass through your milk and harm your baby.
• Have had an allergic reaction to tamoxifen or to any of its inactive ingredients.
• 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:

• You ever had a blood clot that needed medical treatment.
• You are taking medicines to thin your blood, like warfarin, also called Coumadin.
• Your ability to move around is limited for most of your waking hours.
• You are at risk for blood clots. Your doctor can tell you if you are at high risk for blood clots.
• You do not have a higher than normal chance of getting breast cancer. Your doctor can tell you if you are a high-risk woman.

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of tamoxifen there are no specific foods that you must exclude from your diet when receiving tamoxifen.

Tell your doctor if you are pregnant or plan to become pregnant while taking tamoxifen or during the 2 months after you stop taking tamoxifen. Tamoxifen may harm your unborn baby. It takes about 2 months to clear tamoxifen from your body. To be sure you are not pregnant, you can start taking tamoxifen while you are having your menstrual period. Or, you can take a pregnancy test to be sure you are not pregnant before you begin.

Tell your doctor if you are breastfeeding or plan to breastfeed. It is not known if tamoxifen is excreted in human breast milk or if it will harm your nursing baby.

For Women with Ductal Carcinoma in Situ (DCIS) and Women at High Risk for Breast Cancer: Serious and life-threatening events associated with tamoxifen in the risk reduction setting (women at high risk for cancer and women with DCIS) include uterine malignancies, stroke and pulmonary embolism. Incidence rates for these events were estimated from the NSABP P-1 trial. Uterine malignancies consist of both endometrial adenocarcinoma (incidence rate per 1,000 women-years of 2.20 for tamoxifen vs 0.71 for placebo) and uterine sarcoma (incidence rate per 1,000 women-years of 0.17 for Nolvadex vs 0.04 for placebo)*. For stroke, the incidence rate per 1,000 women-years was 1.43 for Nolvadex vs 1.00 for placebo**. For pulmonary embolism, the incidence rate per 1,000 women-years was 0.75 for tamoxifen versus 0.25 for placebo**.

Some of the strokes, pulmonary emboli, and uterine malignancies were fatal.

Health care providers should discuss the potential benefits versus the potential risks of these serious events with women at high risk of breast cancer and women with DCIS considering tamoxifen to reduce their risk of developing breast cancer.

The benefits of tamoxifen outweigh its risks in women already diagnosed with breast cancer.

*Updated long-term follow-up data (median length of follow-up is 6.9 years) from NSABP P-1 study.