pharmacopeia
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/api/v1/drug/toremifene

Boxed warning

QT PROLONGATION FARESTON has been shown to prolong the QTc interval in a dose- and concentration-related manner [see Clinical Pharmacology (12.2) ] . Prolongation of the QT interval can result in a type of ventricular tachycardia called Torsade de pointes, which may result in syncope, seizure, and/or death. Toremifene should not be prescribed to patients with congenital/acquired QT prolongation, uncorrected hypokalemia or uncorrected hypomagnesemia. Drugs known to prolong the QT interval and strong CYP3A4 inhibitors should be avoided [see Warnings and Precautions (5.1) ] . WARNING: QT PROLONGATION FARESTON has been shown to prolong the QTc interval in a dose- and concentration-related manner [see Clinical Pharmacology (12.2) ] . Prolongation of the QT interval can result in a type of ventricular tachycardia called Torsade de pointes, which may result in syncope, seizure, and/or death. Toremifene should not be prescribed to patients with congenital/acquired QT prolongation, uncorrected hypokalemia or uncorrected hypomagnesemia. Drugs known to prolong the QT interval and strong CYP3A4 inhibitors should be avoided [see Warnings and Precautions (5.1) ] .

Mechanism of action

Sourced from openFDA

Toremifene is a nonsteroidal triphenylethylene derivative. Toremifene binds to estrogen receptors and may exert estrogenic, antiestrogenic, or both activities, depending upon the duration of treatment, animal species, gender, target organ, or endpoint selected.

Selective Estrogen Receptor

Indications

Sourced from openFDA
  • FARESTON® is an estrogen agonist/antagonist indicated for the treatment of metastatic breast cancer in postmenopausal women with estrogen-receptor positive or unknown tumors. FARESTON® is an estrogen agonist/antagonist indicated for the treatment of metastatic breast cancer in postmenopausal women with estrogen-receptor positive or unknown tumors.ICD-10: C50.919

Contraindications

Sourced from openFDA
  • Hypersensitivity to the drug ( 4.1 ) QT Prolongation, Hypokalemia, Hypomagnesemia ( 4.2 ) 4.1 Hypersensitivity to the Drug FARESTON is contraindicated in patients with known hypersensitivity to the drug. 4.2 QT Prolongation, Hypokalemia, Hypomagnesemia Toremifene should not be prescribed to patients with congenital/acquired QT prolongation (long QT syndrome), uncorrected hypokalemia, or uncorrected hypomagnesemia.contraindicated

Dosage & administration

Sourced from openFDA

The dosage of FARESTON is 60 mg, once daily, orally. Treatment is generally continued until disease progression is observed. 60 mg once daily, orally ( 2 )

Warnings & precautions

Sourced from openFDA

Prolongation of the QT Interval ( 5.1 ) Heptatotoxicty ( 5.2 ) Hypercalcemia and Tumor Flare ( 5.3 ) Risk of Uterine Malignancy ( 5.4 ) General ( 5.5 ) Laboratory Tests ( 5.6 ) Pregnancy: Fetal harm may occur when administered to a pregnant woman. Women should be advised not to become pregnant when taking FARESTON. ( 5.7 , 8.1 ) Women of Childbearing Potential: Use effective nonhormonal contraception during FARESTON therapy. ( 5.8 ) 5.1 Prolongation of the QT Interval Toremifene has been shown to prolong the QTc interval in a dose- and concentration-related manner [see Clinical Pharmacology (12.2) ] . Prolongation of the QT interval can result in a type of ventricular tachycardia called Torsade de pointes, which may result in syncope, seizure, and/or death. 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. Hypokalemia or hypomagnesemia must be corrected prior to initiating toremifene and these electrolytes should be monitored periodically during therapy. 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 [see Drug Interactions (7.2) and Clinical Pharmacology (12.2) ] .

Adverse reactions

Sourced from openFDA

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. Most common adverse reactions are hot flashes, sweating, nausea and vaginal discharge. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Kyowa Kirin, Inc. at 1-800-305-FARESTON (1-800-305-3273) or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trials Experience Adverse drug reactions are principally due to the antiestrogenic actions of FARESTON and typically occur at the beginning of treatment. The incidences of the following eight clinical toxicities were prospectively assessed in the North American Study. The incidence reflects the toxicities that were considered by the investigator to be drug related or possibly drug related. North American Study FAR60 TAM20 n = 221 n = 215 Hot Flashes 35% 30% Sweating 20% 17% Nausea 14% 15% Vaginal Discharge 13% 16% Dizziness 9% 7% Edema 5% 5% Vomiting 4% 2% Vaginal Bleeding 2% 4% Approximately 1% of patients receiving FARESTON (n = 592) in the three controlled studies discontinued treatment as a result of adverse reactions (nausea and vomiting, fatigue, thrombophlebitis, depression, lethargy, anorexia, ischemic attack, arthritis, pulmonary embolism, and myocardial infarction). Serious adverse reactions occurring in at least 1% of patients receiving FARESTON in the three major trials are listed in the table below.

Use in specific populations

Sourced from openFDA

Nursing Mothers: Discontinue drug or nursing taking into account the importance of the drug to the mother. ( 8.2 ) 8.1 Pregnancy Pregnancy Category D [see Warnings and Precautions (5.7) .] 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. Toremifene caused embryo-fetal toxicities at maternal doses that were lower than the 60 mg daily recommended human dose on a mg/m 2 basis. There are no adequate and well-controlled studies in pregnant women using FARESTON. If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be apprised of the potential hazard to the fetus. In animal studies, toremifene crossed the placenta and accumulated in the rodent fetus. Administration of toremifene to pregnant rats during organogenesis at doses of approximately 6% the daily maximum recommended human dose of 60 mg (on a mg/m 2 basis) resulted in signs of maternal toxicity and increased preimplantation loss, increased resorptions, reduced fetal weight, and fetal anomalies. Fetal anomalies include malformation of limbs, incomplete ossification, misshapen bones, ribs/spine anomalies, hydroureter, hydronephrosis, testicular displacement, and subcutaneous edema.

Pharmacokinetics

Sourced from openFDA
Metabolism
Absorption - Toremifene is well absorbed after oral administration and absorption is not influenced by food. Peak plasma concentrations are obtained within 3 hours.

Overdosage

Sourced from openFDA

Lethality was observed in rats following single oral doses that were ≥1000 mg/kg (about 150 times the recommended human dose on a mg/m 2 basis) and was associated with gastric atony/dilatation leading to interference with digestion and adrenal enlargement. Vertigo, headache, and dizziness were observed in healthy volunteer studies at a daily dose of 680 mg for 5 days. The symptoms occurred in two of the five subjects during the third day of the treatment and disappeared within 2 days of discontinuation of the drug. No immediate concomitant changes in any measured clinical chemistry parameters were found. In a study in postmenopausal breast cancer patients, toremifene 400 mg/m 2 /day caused dose-limiting nausea, vomiting, and dizziness, as well as reversible hallucinations and ataxia in one patient. Theoretically, overdose may be manifested as an increase of antiestrogenic effects, such as hot flashes; estrogenic effects, such as vaginal bleeding; or nervous system disorders, such as vertigo, dizziness, ataxia, and nausea. There is no specific antidote and the treatment is symptomatic.

Approval history

Sourced from openFDA
  • May 29, 1997NDANDA020497Kyowa Kirin
  • Dec 4, 2018ANDAANDA208813Rising
  • Aug 18, 2020ANDAANDA212818Msn

FAERS reports

View JSON
Reference statistics only. FAERS reports are voluntarily submitted and are not incidence rates, safety signals, or causal evidence. Counts reflect reporting volume — how often a reaction was reported, not how often it occurs. For decision-grade use, consult openFDA and the FAERS Public Dashboard directly.
421 total reports matchedLatest report Share = reports listing the reaction ÷ total matched reports. Rows can sum to >100% because a single report often lists multiple reactions.
  1. 1Interstitial Lung Disease225.2%
  2. 2Hepatic Function Abnormal215.0%
  3. 3Osteonecrosis Of Jaw194.5%
  4. 4White Blood Cell Count Decreased184.3%
  5. 5Osteomyelitis163.8%
  6. 6Fatigue153.6%
  7. 7Malignant Neoplasm Progression153.6%
  8. 8Anaemia122.9%
  9. 9Aspartate Aminotransferase Increased122.9%
  10. 10Oedema Peripheral122.9%
  11. 11Pain122.9%
  12. 12Pyrexia122.9%
  13. 13Endometrial Hypertrophy112.6%
  14. 14Malaise112.6%
  15. 15Osteonecrosis112.6%

Literature

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Recent PubMed references pinned to Toremifene as a MeSH major topic. Citations link to pubmed.ncbi.nlm.nih.gov.

Clinical trials

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The 10 most recently updated of 40 ClinicalTrials.gov registrations naming Toremifene as an intervention. Registration is not evidence of efficacy or safety — reference crosswalk only.

Frequently asked questions

How does Toremifene work?
Toremifene is a nonsteroidal triphenylethylene derivative. Toremifene binds to estrogen receptors and may exert estrogenic, antiestrogenic, or both activities, depending upon the duration of treatment, animal species, gender, target organ, or endpoint selected.
What is Toremifene used for?
According to FDA labeling, Toremifene carries indications including: FARESTON® is an estrogen agonist/antagonist indicated for the treatment of metastatic breast cancer in postmenopausal women with estrogen-receptor positive or unknown tumors. FARESTON® is an estrogen agonist/antagonist indicated for the treatment of metastatic breast cancer in postmenopausal women with estrogen-receptor positive or unknown tumors.. This is a reference summary of labeled uses, not medical advice or a treatment recommendation.
What class of drug is Toremifene?
Toremifene is classified as Anti-estrogens, Estrogen Agonist/Antagonist, Selective Estrogen Receptor Modulators, Decreased DNA Replication, Decreased Ovarian Estrogen Secretion.
What are the brand names for Toremifene?
Toremifene is marketed under brand names including Fareston.
What are the contraindications for Toremifene?
Toremifene labeling lists contraindications including: Hypersensitivity to the drug ( 4.1 ) QT Prolongation, Hypokalemia, Hypomagnesemia ( 4.2 ) 4.1 Hypersensitivity to the Drug FARESTON is contraindicated in patients with known hypersensitivity to the drug. 4.2 QT Prolongation, Hypokalemia, Hypomagnesemia Toremifene should not be prescribed to patients with congenital/acquired QT prolongation (long QT syndrome), uncorrected hypokalemia, or uncorrected hypomagnesemia.. Always consult the full prescribing information and a clinician.
Note. Data for toremifene is illustrative MVP content compiled from public sources. pharmacopeia is for educational and informational use only and is not a substitute for professional medical advice.

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