Health Library

Toremifene (By mouth)

Toremifene Citrate (tore-EM-i-feen SIT-rate)

Treats breast cancer in postmenopausal (no longer have menstrual periods) women.

Brand Name(s):

Fareston

When This Medicine Should Not Be Used:

How to Use This Medicine:

Tablet

• Medicines used to treat cancer are very strong and can have many side effects. Before receiving this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.
• Your doctor will tell you how much medicine to use. Do not use more than directed.
• Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
• Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.

Drugs and Foods to Avoid:

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

• Some medicines can affect how toremifene works. Tell your doctor if you are using any of the following:
  • Atazanavir, carbamazepine, dexamethasone, granisetron, indinavir, itraconazole, ketoconazole, midazolam, nefazodone, nelfinavir, ondansetron, phenobarbital, phenytoin, rifabutin, rifampin, ritonavir, saquinavir, St John's wort, tolbutamide, voriconazole
  • Diuretic (water pill)
  • Medicine for depression or mental health problems
  • Medicine for heart rhythm problems
  • Medicine to treat an infection
• Do not eat grapefruit or drink grapefruit juice while you are using this medicine.

Warnings While Using This Medicine:

• Pregnancy after menopause is not likely, but if you think you could be pregnant, tell your doctor. This medicine could harm an unborn baby. If you are a woman who can bear children, your doctor may give you a pregnancy test before you start using this medicine to make sure you are not pregnant. Women should use an effective form of birth control during treatment with toremifene.
• Tell your doctor if you are breastfeeding, or if you have liver disease (including cirrhosis), congestive heart failure, bone problems (including bone cancer), uterus problems, or a history of blood clots.
• This medicine may cause the following problems:
  • Changes in heart rhythm, including QT prolongation
  • Liver problems
  • Tumor flare (increased size of a tumor)
  • Uterus (womb) problems
• This medicine may make you bleed, bruise, or get infections more easily. Take precautions to prevent illness and injury. Wash your hands often.
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine:

Call your doctor right away if you notice any of these side effects:

• Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
• Confusion, constipation, dry mouth, thirst, unusual tiredness
• Dark urine or pale stools, nausea, vomiting, loss of appetite, stomach pain, yellow skin or eyes
• Fainting, dizziness, lightheadedness, fast, pounding, or uneven heartbeat
• Fever, chills, cough, sore throat, body aches
• Swelling in your hands, ankles, or feet
• Unusual bleeding, bruising, weakness
• Vaginal bleeding or discharge

If you notice these less serious side effects, talk with your doctor:

• Dizziness
• Sweating
• Warmth or redness in your face, neck, arms, or upper chest

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Last Updated: 9/6/2024