Brand Names

Category

• Antineoplastic

Description

Toremifene (TORE-em-i-feen) is a medicine that blocks the effects of the estrogen hormone in the body. It is used to treat breast cancer in women.

The exact way that toremifene works against cancer is not known but it may be related to the way it blocks the effects of estrogen in the body.

Before you begin treatment with toremifene, you and your doctor should talk about the good this medicine will do as well as the risks of using it.

Toremifene is available only with your doctor's prescription, in the following dosage form:

Oral
• Tablets (U.S.)

Before Using This Medicine

In deciding to use a medicine, the risks of taking [using] the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For toremifene, the following should be considered:

Allergies--Tell your doctor if you have ever had any unusual or allergic reaction to toremifene.

Pregnancy--Tell your doctor if you are pregnant or if you intend to become pregnant. Studies in rats and rabbits have shown that toremifene causes miscarriages, birth defects, and death of the fetus. Studies in animals have also shown that toremifene may cause some of the same problems as an estrogen called diethylstilbestrol (DES). DES causes genital tract problems and, rarely, an increased risk of cancer of the cervix or vagina in daughters of women who took it during their pregnancy; it is not known whether toremifene causes these same problems.

Tell your doctor right away if you think you have become pregnant while taking toremifene.

Other medicines--Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking toremifene, it is especially important that your health care professional know if you are taking any of the following:

• Anticoagulants, coumarin-type (blood thinners)--Use with this medicine may increase the amount of time it takes blood to clot

• Carbamazepine (e.g., Tegretol) or
• Phenobarbital or
• Phenytoin (e.g., Dilantin)--These medicines may decrease blood levels of toremifene, which could make it less effective

Other medical problems--The presence of other medical problems may affect the use of toremifene. Make sure you tell your doctor if you have any other medical problems, especially:

• Blood clots (history of)--Use of toremifene is usually not recommended

• Unusual growth of the lining of the uterus (womb)--Long-term use of toremifene is usually not recommended

Proper Use of This Medicine

Dosing--The dose of toremifene will be different for different patients. Follow your doctor's orders or the directions on the label . The following information includes only the average doses of toremifene. If your dose is different, do not change it unless your doctor tells you to do so.

• For oral dosage form (tablets):
  • For breast cancer:
    • Adults--60 milligrams (mg) once a day.

Storage--To store this medicine:

• Keep out of the reach of children.
• Store away from heat and direct light.
• Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
• Do not keep outdated medicine or medicine no longer needed. Be sure that any discarded medicine is out of the reach of children.

Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects. Some side effects will have signs or symptoms that you can see or feel. Your doctor will watch for others by doing certain tests.

Also, because of the way this medicine acts on the body, there is a chance that it might cause other unwanted effects that may not occur until months or years after the medicine is used. Some patients who have used toremifene have developed cancer of the uterus (womb), although it is not known for sure if it was caused by the medicine. Discuss this possible effect with your doctor.

Check with your doctor as soon as possible if any of the following side effects occur:

Less common

Blurred vision; change in vaginal discharge; changes in vision; confusion; increased urination; loss of appetite; pain or feeling of pressure in pelvis; unusual tiredness; vaginal bleeding

Rare

Chest pain; pain or swelling of feet or legs; shortness of breath

This medicine may also cause the following side effect(s) that your doctor will watch for:

Less common