Toremifene

What is Toremifene?

• Toremifene (Fareston) is an estrogen agonist/antagonist used in the treatment of estrogen receptor positive breast cancer.

Toremifene

Toremifene molecule ball

What are the uses of this medicine?

Toremifene (Fareston) is approved to treat:

• Breast cancer that has metastasized (spread to other parts of the body). It is used in postmenopausal women whose cancer is estrogen receptor positive (ER+) or when it is not known if the cancer is ER+ or estrogen receptor negative (ER-).

How does this medicine work?

• Toremifene (tor em' i feen) is a selective estrogen receptor modulator, similar to tamoxifen, that has tissue specific actions with antiestrogenic activity on breast tissue, but estrogenic activity (agonism) on bone and the cardiovascular system.
• The antiestrogenic effects of toremifene are the basis for its use in the treatment of estrogen-receptor positive breast cancer.
• It also has weak estrogenic effects on uterus.

Who Should Not Use this medicine ?

This medicine cannot be used in patients with:

• known hypersensitivity to the drug.
• congenital/acquired QT prolongation (long QT syndrome), uncorrected hypokalemia, or uncorrected hypomagnesemia.

What drug interactions can this medicine cause?

Tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention 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)
• verapamil (Calan, Covera, Isoptin, Verelan)

Is this medicine FDA approved?

Toremifene was approved for use in the United States in 1997 and its indications are limited to the treatment of estrogen-receptor positive (or unknown) metastatic breast cancer in postmenopausal women. Unlike tamoxifen, toremifene has not been approved as a means of prevention of de novo breast cancer in high risk patients or for prevention of recurrence of breast cancer.

How should this medicine be used?

Recommended dosage:

• The dosage of Fareston is 60 mg, once daily, orally.

Administration:

• Toremifene comes as a tablet to take by mouth.
• It is taken with or without food once a day.
• Take toremifene at around the same time every day.
• Take toremifene exactly as directed.
• Do not take more or less of it or take it more often than prescribed by your doctor.

What are the dosage forms and brand names of this medicine?

This medicine is available in fallowing doasage form:

• As 60 mg tablet

This medicine is available in fallowing brand namesː

• Fareston

What side effects can this medication cause?

The most common side effects of this medicine include:

• hot flashes
• sweating
• nausea
• vaginal discharge
• dizziness
• peripheral edema

• Rare, but potentially severe adverse events include tumor flare (transient worsening soon after starting therapy), prolongation of the QTc interval, venous thrombosis and pulmonary embolism and endometrial (uterine) carcinoma.

What special precautions should I follow?

• Toremifene has been shown to prolong the QTc interval in a dose- and concentration-related manner. Toremifene should be avoided in patients with long QT syndrome. Caution should be exercised in patients with congestive heart failure, hepatic impairment and electrolyte abnormalities. Drugs that prolong the QT interval should be avoided. In patients at increased risk, electrocardiograms (ECGs) should be obtained at baseline and as clinically indicated.
• Hepatotoxicity have also been reported in clinical trials and postmarketing with Fareston. Liver function tests should be performed periodically.
• As with other antiestrogens, hypercalcemia and tumor flare have been reported in some breast cancer patients with bone metastases during the first weeks of treatment with Fareston. If hypercalcemia occurs, appropriate measures should be instituted and, if hypercalcemia is severe, Fareston treatment should be discontinued.
• Endometrial cancer, endometrial hypertrophy, hyperplasia, and uterine polyps have been reported in some patients treated with Fareston. All patients should have baseline and annual gynecological examinations.
• Leukopenia and thrombocytopenia have been reported rarely; leukocyte and platelet counts should be monitored when using Fareston in patients with leukopenia and thrombocytopenia.
• Periodic complete blood counts, calcium levels, and liver function tests should be obtained.
• Based on its mechanism of action in humans and findings of increased pregnancy loss and fetal malformation in animal studies, Fareston can cause fetal harm when administered to a pregnant woman.
• Long term toremifene therapy has been associated with development of fatty liver, steatohepatitis, cirrhosis, and rare instances of clinically apparent acute liver injury.

What to do in case of emergency/overdose?

Symptoms of overdosage may include:

• Vertigo
• headache
• dizziness
• nausea
• vomiting
• hallucinations
• ataxia
• hot flashes
• vaginal bleeding

Management of overdosage:

• There is no specific antidote and the treatment is symptomatic.

Can this medicine be used in pregnancy?

• Pregnancy Category D
• Based on its mechanism of action in humans and findings of increased pregnancy loss and fetal malformation in animal studies, Fareston can cause fetal harm when administered to a pregnant woman.

Can this medicine be used in children?

• There is no indication for use of Fareston in pediatric patients.

What are the active and inactive ingredients in this medicine?

Active ingredients include:

• TOREMIFENE CITRATE

Inactive ingredients include:

• SILICON DIOXIDE
• ANHYDROUS LACTOSE
• MAGNESIUM STEARATE
• MICROCRYSTALLINE CELLULOSE
• POVIDONE, UNSPECIFIED
• SODIUM STARCH GLYCOLATE TYPE A POTATO
• STARCH, CORN

Who manufactures and distributes this medicine?

Distributed by

• Kyowa Kirin, Inc.
• Bedminster, NJ, USA

What should I know about storage and disposal of this medication?

• Store at 25°C (77°F).
• Excursions permitted to 15-30°C (59-86°F).
• Protect from heat and light.

• Dailymed label info on Toremifene
• FDA Toremifene

Toremifene Resources
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