Toremifene Citrate

Toremifene Citrate (CAS No. 89778-27-8) is a selective estrogen receptor modulator (SERM). Its core bioactivity is to modulate estrogen receptor (ERα, ERβ) function, with both receptor antagonistic and tissue-selective agonistic effects. It mainly inhibits the proliferation of estrogen-dependent tumor cells and is used for the treatment of estrogen receptor–positive metastatic breast cancer in postmenopausal women. Its IC?? values are receptor-specific, with an IC?? of about 19 nM for human ERα and about 26 nM for ERβ (competitive binding assay). In vitro, it inhibits the proliferation of breast cancer cell lines (such as MCF-7) with an EC?? of about 1-10 μM. Common application concentrations: in vitro cell experiments typically use a gradient of 0.1-100 μM (for receptor binding, proliferation inhibition, and signaling pathway studies). In animal experiments, oral doses of 5-50 mg/kg/day in rat/mouse tumor models can inhibit breast tumor growth. Clinically effective therapeutic concentrations correspond to an adult oral dose of 60 mg once daily, with a steady-state plasma peak concentration of about 1.5-3 μg/mL. The drug is metabolized in the liver, with a half-life of about 3-7 days, and the dose should be adjusted according to liver function. Concomitant use with strong CYP3A4 inhibitors should be avoided. Common adverse reactions include hot flashes, vaginal bleeding, and nausea.

References:

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