Description: Toremifene, a non-steroidal triphenylethylene derivative, blocks the growth-inducing effect of oestrogen by competing with its binding sites.


Absorption: Well absorbed from GI tract. Peak plasma concentrations within 3 hr.

Distribution: Protein-binding: Extensive, mainly to albumin.

Metabolism: Metabolised mainly by the cytochrome P450 isoenzyme CYP3A4 to less active metabolites.

Excretion: Excreted mainly in faeces and in urine (10%) as metabolites. Undergoes enterohepatic circulation.

Toremifene, a nonsteroidal antiestrogen, slows or stops the growth of metastatic breast cancer (breast cancer that has spread to the other parts of the body) of menopausal women.

How to use toremifene

Take this medication by mouth with or without food, usually once daily or as directed by your doctor. Dosage is based on your medical condition and response to therapy.

Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.

Avoid eating grapefruit or drinking grapefruit juice while using this medication unless your doctor or pharmacist says you may do so safely. Grapefruit can increase the chance of side effects with this medicine. Ask your doctor or pharmacist for more details.

Since this drug can be absorbed through the skin and lungs, women who are pregnant or who may become pregnant should not handle this medication or breathe the dust from the tablets.

Inform your doctor immediately if your condition worsens (e.g., you get new breast lumps).

Toremifene has caused very serious (possibly fatal) heart rhythm problems (QT prolongation in the EKG, torsades de pointes). Low levels of potassium or magnesium in the blood may also increase your risk of QT prolongation.

Notify your doctor promptly if any of these side effects persist or worsen:

  • hot flashes
  • sweating
  • nausea
  • vomiting
  • dry eyes
  • dizziness

Tell your doctor immediately if any of these unlikely but serious side effects occur:

  • bone/joint/muscle pain or swelling
  • constipation
  • mental/mood changes (e.g., depression)
  • trouble walking/clumsiness
  • swelling ankles/feet
  • unusual tiredness
  • vision changes (e.g., blurred vision, eye pain)

Toremifene may increase your risk of uterine cancer.

Tell your doctor immediately if any of these rare but very serious side effects occur:

  • easy bleeding/bruising
  • signs of infection (e.g., fever, chills, persistent sore throat)
  • persistent nausea/vomiting
  • severe abdominal/stomach pain
  • dark urine
  • yellowing eyes/skin

Toremifene has rarely caused very serious (possibly fatal) blood clots in the lungs/legs, brain (stroke), and heart (heart attack).

A very serious allergic reaction to this drug is rare.

This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.


  • Allergic reaction to this medication.
  • Patients with medical history of:
    • bone cancer (metastases)
    • blood disorders (e.g., anemia, low platelets)
    • diabetes
    • history of stroke or other blood clots (e.g., in the legs, lungs)
    • heart disease (e.g., heart attack, irregular heartbeat)
    • high blood pressure
    • liver disease
    • long periods of sitting or lying down (e.g., immobility such as being bedridden)
    • uterus problems such as endometrial hyperplasia
  • This drug may make you dizzy.
  • Notify your doctor beforehand if you will be having surgery or will be confined to a chair/bed for a long time (e.g., a long plane flight).
  • Used only when clearly needed during pregnancy.
  • Consult your doctor before breast-feeding.

Consult your doctor regarding the precautions mentioned above.


Some products that may interact with this drug include:

  • “blood thinners” (e.g., warfarin)
  • estrogens
  • “water pills” (diuretics such as hydrochlorothiazide)
  • drugs affecting liver enzymes that remove toremifene from your body (e.g., certain anti-seizure medications such as carbamazepine/clonazepam/phenobarbital/phenytoin, rifampin)


If overdose is suspected, contact a poison control center or emergency room immediately.


Do not share this medication with others.

Laboratory and/or medical tests (e.g., complete blood count, calcium levels, liver tests) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.

Missed Dose

If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.


Store at room temperature at 77 degrees F (25 degrees C) away from light and moisture. Brief storage between 59-86 degrees F (15-30 degrees C) is permitted. Do not store in the bathroom. Keep all medicines away from children and pets.

Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company for more details about how to safely discard your product.


There are no brands containing this molecule.

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