Toremifene (Fareston)

Toremifene, commonly sold under the brand name Fareston, is a medication primarily used in the treatment of advanced breast cancer in postmenopausal women with estrogen-receptor-positive or unknown tumors.

Here is a detailed breakdown of the information you requested:

Detailed Explanation / Different Name

• Different Name (Brand Name): Fareston is the most common brand name.

• Classification: Toremifene is classified as a Selective Estrogen Receptor Modulator (SERM).

• Mechanism of Action: As a SERM, it acts as a mixed agonist-antagonist of the estrogen receptor (ER). This means it has different effects in different tissues:

  • Antiestrogenic effects in the breast: It blocks estrogen from binding to its receptors on breast cancer cells, which limits the cancer's growth.

  • Estrogenic (agonist) effects in other tissues: It mimics estrogen's effects in tissues like the bone (helping to maintain bone mineral density) and the liver (affecting cholesterol levels).

• Chemical Relation: It is a triphenylethylene derivative, closely related to another common SERM, tamoxifen.

Side Effects and Benefits

Pros and Cons

Dosage and Frequency

• Dosage: The standard dose for the treatment of metastatic breast cancer is 60 mg.

• Frequency: Once daily (orally).

• Duration: Treatment is generally continued until disease progression is observed.

Half-Life and Detection Time

• Half-Life (t1/2​): The terminal elimination half-life of Toremifene is approximately 5 days.

• Detection Time: Based on the half-life, it takes approximately 5 half-lives for a drug to be almost completely eliminated (≈97%). For Toremifene, this would be about 25 days (5 days × 5). However, drug detection times in anti-doping contexts can vary significantly and often rely on the detection of metabolites in urine/blood, which can be much longer than the parent drug's elimination time. For anti-doping purposes, detection windows for SERMs can sometimes be weeks to months. Specific, reliable detection times for all metabolites in sport testing are often proprietary or not definitively published for non-therapeutic use.

Sterogenic, Progestronic, Prolactin Effects

• Sterogenic (Estrogenic/Antiestrogenic): Toremifene is primarily an antiestrogen in breast tissue and an estrogen agonist in bone, liver, and uterus. It significantly increases levels of Sex Hormone-Binding Globulin (SHBG) in the liver (an estrogenic effect). It also impacts the hypothalamic-pituitary axis.

• Progestronic: Toremifene is not a progestogen and does not bind significantly to the progesterone receptor.

• Prolactin Affects: Toremifene has been observed to cause a decrease in prolactin levels in men. In postmenopausal women, it may not significantly affect prolactin.

Anabolic Androgenic Ratio

• Toremifene is NOT an Anabolic-Androgenic Steroid (AAS).

• It is a Selective Estrogen Receptor Modulator (SERM).

• Therefore, it does not have an Anabolic:Androgenic ratio in the way that testosterone-derived steroids do (like 1:1, 1:10, etc.). Its primary mechanism is via the estrogen receptor, not the androgen receptor. It is not generally considered to have anabolic effects.