Talk to your doctor or pharmacist before taking Tamoxifen.
In delayed breast reconstruction operation (weeks to years after the primary breast operation when your own tissue is moved to shape a new breast) Tamoxifen may increase the risk of the formation of blood clots in the small vessels of the tissue flap which may lead to complications.
Studies in premenopausal women who took tamoxifen for reduction of breast cancer risk or for treatment of breast cancer have reported decreases in bone density. If you are a premenopausal woman undergoing treatment with Tamoxifen, ask your doctor for advice about ways to maintain your bone health.
Tamoxifen therapy may be used to reduce the risk of breast cancer and it can be associated with serious side effects such as blood clots in the veins of your leg (deep vein thrombosis), blood clots in your lungs (pulmonary embolus) and uterine cancer, all of which can be fatal. Other less serious side effects such as hot flushes, vaginal discharge, menstrual irregularities and pelvis pain may also occur.
Whether the benefits of treatment outweigh the risks depends on your age, health history, your level of breast cancer risk and on your personal judgement. Tamoxifen therapy to reduce the risk of breast cancer may not be appropriate for all women at increased risk. All assessments with your healthcare professional of the potential benefits and risks prior to starting therapy are essential. You should understand that Tamoxifen reduces, but does not eliminate the risk of breast cancer.
If you have or have had heart problems or an irregular heartbeat (arrhythmia), you may be at a higher risk of changes in your heart’s electrical activity (known as QT prolongation) when using tamoxifen. QT prolongation can be seen on a heart test called an electrocardiogram (ECG) and may increase the risk of serious heart rhythm problems. If you are at an increased risk, your doctor should check your blood for important blood salts and minerals (electrolytes) and check your heart activity with an ECG before and during treatment with tamoxifen.
If you have a history of hereditary angioedema as Tamoxifen may cause or worsen symptoms of hereditary angioedema. If you experience symptoms such as swelling of the face, lips, tongue and/or throat with difficulty in swallowing or breathing, contact a doctor immediately.
If you have any heart conditions including heart rhythm problems (arrhythmia), including a condition called Long QT syndrome (QT interval prolongation), the risk of heart rhythm problems may be increased when using Tamoxifen.
Serious skin reactions
Serious skin reactions including Stevens-Johnson syndrome and toxic epidermal necrolysis, have been reported in association with Tamoxifen treatment. Stop using Tamoxifen and seek medical attention immediately if you notice any of the symptoms related to these serious skin reactions described in section 4.