What is toremifene?
Toremifene blocks estrogen from reaching cancer cells. Certain types of breast cancer require estrogen to grow.
Toremifene is used to slow the growth of metastatic breast cancer (cancer that has spread from the original tumor). Unlike chemotherapy, toremifene does not actually destroy cancer cells.
Toremifene may also be used for purposes not listed in this medication guide.
What is the most important information I should know about toremifene?
Do not use toremifene if you are pregnant. It could harm the unborn baby.
You should not use toremifene if you are allergic to it, or if you have a history of Long QT syndrome, or an uncontrolled electrolyte imbalance (low levels of potassium or magnesium in your blood).
Before you take toremifene, tell your doctor if you have endometrial hyperplasia (overgrowth of cells lining the uterus), bone cancer, or if you have ever had a blood clot.
Taking toremifene may increase your risk of developing endometrial hyperplasia, a condition that may lead to cancer of the uterus. Talk to your doctor about your individual risk.
Stop using toremifene and call your doctor at once if you have symptoms of a serious heart rhythm disorder (severe dizziness, fainting, fast or pounding heartbeats) or signs of high levels of calcium in your blood (nausea, vomiting, stomach pain, loss of appetite, constipation, increased thirst or urination, muscle pain or weakness, joint pain, confusion, and feeling tired or restless).
What should I discuss with my healthcare provider before taking toremifene?
You should not use toremifene if you are allergic to it, or if you have:
To make sure you can safely take toremifene, tell your doctor if you have any of these other conditions:
FDA pregnancy category D. Do not use toremifene if you are pregnant. It could harm the unborn baby. Use effective birth control if you are not past menopause, and tell your doctor if you become pregnant during treatment.
It is not known whether toremifene passes into breast milk or if it could harm a nursing baby. You should not breast-feed while you are using toremifene.
Taking toremifene may increase your risk of developing endometrial hyperplasia, a condition that may lead to cancer of the uterus. Talk to your doctor about your individual risk.