Toremifene is used to treat breast cancer that has spread to other parts of the body in women who have experienced menopause (‘change of life’; end of monthly menstrual periods). Toremifene is in a class of medications called nonsteroidal antiestrogens. It works by blocking the activity of estrogen (a female hormone) in the breast. This may stop the growth of some breast tumors that need estrogen to grow.

Side Effects Of Toremifene

Toremifene may cause side effects. Tell your doctor if any of these symptoms are severe or do not go away:

  • hot flashes
  • sweating
  • blurred or abnormal vision
  • sensitivity to light or seeing halos around lights
  • difficulty seeing at night
  • fading or yellowing of colors
  • dry eyes
  • dizziness
  • swelling of the hands, feet, ankles, or lower legs

Some side effects can be serious. If you experience any of these symptoms or those listed in the WARNINGS section, call your doctor immediately:

  • vaginal bleeding
  • pelvic pain or pressure
  • irregular periods
  • unusual vaginal discharge
  • sleepiness
  • confusion
  • muscle pain or weakness
  • joint pain
  • abdominal pain
  • constipation
  • frequent urination
  • excessive thirst
  • loss of appetite
  • nausea
  • vomiting
  • Some people who took toremifene developed cancer of the lining of the uterus. There is not enough information to tell if toremifene caused these people to develop cancer. Talk to your doctor about the risks of taking this medication.

Toremifene may cause other side effects. Call your doctor if you have any unusual problems while taking this medication.

Warnings & Precautions

Before taking toremifene:

  • tell your doctor and pharmacist if you are allergic to toremifene, any other medications, or any of the ingredients in toremifene tablets. Ask your pharmacist for a list of the ingredients.
  • tell your doctor and pharmacist what prescription and nonprescription medications, vitamins, and nutritional supplements you are taking or plan to take. Be sure to mention the medications listed in the WARNINGS section and any of the following: anticoagulants (”blood thinners”) such as warfarin (Coumadin); carbamazepine (Epitol, Equetro, Tegretol); cimetidine (Tagamet); clonazepam (Klonopin); dexamethasone (Decadron, Dexone); diltiazem (Cardizem, Dilacor, Tiazac, others); diuretics (‘water pills’); fluvoxamine; phenobarbital; phenytoin (Dilantin, Phenytek); rifabutin (Mycobutin); rifampin (Rifadin, Rimactane); and verapamil (Calan, Covera, Isoptin, Verelan). Your doctor may need to change the doses of your medications or monitor you carefully for side effects. Many other medications may also interact with toremifene, so be sure to tell your doctor about all the medications you are taking, even those that do not appear on this list.
  • tell your doctor what herbal products you are taking, especially St. John’s wort.
  • tell your doctor if your cancer has spread to your bones and if you have or have ever had any condition that causes your blood to clot more easily than normal or endometrial hyperplasia (overgrowth of the lining of the uterus).
  • tell your doctor if you are pregnant, plan to become pregnant, or are breast-feeding. If you become pregnant while taking toremifene, call your doctor. Toremifene may harm the fetus. If you have not experienced menopause, you should use a reliable nonhormonal method of birth control to prevent pregnancy while you are taking toremifene.
  • if you are having surgery, including dental surgery, tell the doctor or dentist that you are taking toremifene.
  • you should know that your tumor may grow slightly bigger when you begin treatment with toremifene. If this happens, you may experience redness of the skin and bone pain. This is normal and does not mean that your cancer is worsening. As you continue your treatment with toremifene, your tumor will shrink.

Toremifene Dosage

Toremifene comes as a tablet to take by mouth. It is usually taken with or without food once a day. Take toremifene at around the same time every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take toremifene exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.


Do not let anyone else take your medication. Ask your pharmacist any questions you have about refilling your prescription.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.


All information has been provided courtesy of MedLinePlus from the National Library of Medicine and from the FDA.