Fareston Toremifene Citrate Tablets

1. Indications and Usage
Metastatic Breast Cancer:
Treatment of metastatic breast cancer in postmenopausal women with estrogen receptor (ER)-positive or unknown status tumors.
2. Dosage and Administration
Route of Administration:
Oral administration.
Recommended Dosage:
Standard Dose: 60 mg once daily.
Titration: In patients with uncontrolled seizures or severe cardiac insufficiency, the dose may need to be reduced based on individual tolerance.
Critical Administration Instructions:
With Food: It is recommended to take the tablets with food or immediately following a meal.
Adherence: Patients should be advised to take this medication at the same time each day to maintain consistent blood levels.
3. Mechanism of Action
SERM Activity:
Toremifene is a non-steroidal triphenylethylene derivative. It competes with estrogen for binding to estrogen receptors in the target tissues (primarily the breast).
Antiestrogenic Effect:
By blocking estrogen receptors, it inhibits the proliferation and DNA synthesis of estrogen-dependent tumor cells.
Note: While it acts as an antagonist in breast tissue, it may exhibit estrogen-like effects in other tissues (e.g., bone, liver, endometrium).
4. Safety and Warnings
Thromboembolic Events:
Similar to other SERMs, Toremifene increases the risk of thromboembolic events, including deep vein thrombosis (DVT) and pulmonary embolism (PE).
Endometrial Changes:
The estrogen-like effect may lead to endometrial hyperplasia, polyps, or endometrial cancer.
Action: Patients should undergo regular gynecological examinations.
QT Prolongation:
Toremifene may prolong the QT interval.
Action: Use with caution in patients with cardiac insufficiency or those taking other drugs known to prolong the QT interval.
Hypercalcemia:
Hypercalcemia may occur in patients with bone metastases shortly after initiating treatment.
Contraindications:
History of endometrial hyperplasia.
Severe hepatic insufficiency.
Adverse Reactions and Clinical Research
Most Common Adverse Reactions:
Hot flashes, sweating, vaginal bleeding, vaginal discharge, fatigue, nausea, rash, dizziness, and headache.
Clinical Research Highlights:
Efficacy: Clinical trials have demonstrated that Toremifene is as effective as Tamoxifen in treating metastatic breast cancer in postmenopausal women.
Safety Comparison: Toremifene generally shows a lower incidence of endometrial cancer compared to Tamoxifen, though the risk of thromboembolic events remains comparable.
Drug Interactions
Anticoagulants:
Concomitant use with coumarin-type anticoagulants (e.g., Warfarin) may lead to excessive prolongation of bleeding time.
CYP3A4 Inhibitors:
Toremifene is metabolized by CYP3A4. Co-administration with potent inhibitors (e.g., Ketoconazole, Erythromycin) should be approached with caution.
Inducers of Metabolism:
Enzyme inducers (e.g., Carbamazepine, Phenytoin, Phenobarbital) may accelerate metabolism, potentially requiring dose adjustment.
Calcium Metabolism:
Drugs that reduce renal calcium excretion (e.g., Thiazide diuretics) may increase the risk of hypercalcemia.
Pharmaceutical Information
Chemical Composition:
Active Ingredient: Toremifene Citrate.
Appearance: White or off-white, oval or round tablets (60 mg).
Packaging: Blister packs or Bottles (e.g., 30 tablets).
Storage: Store at controlled room temperature (20°C to 25°C).