Toremifene, sold under the brand name Fareston among others, is a medication which is used in the treatment of advanced breast cancer in postmenopausal women. It is taken by mouth.Side effects of toremifene include hot flashes, sweating, nausea, vomiting, dizziness, vaginal discharge, and vaginal bleeding. It can also cause blood clots, irregular heartbeat, cataracts, visual disturbances, elevated liver enzymes, endometrial hyperplasia, and endometrial cancer. High blood calcium levels can occur in women with bone metastases.The medication is a selective estrogen receptor modulator (SERM) and hence is a mixed agonist–antagonist of the estrogen receptor (ER), the biological target of estrogens like estradiol. It has estrogenic effects in bone, the liver, and the uterus and antiestrogenic effects in the breasts. It is a triphenylethylene derivative and is closely related to tamoxifen.Toremifene was introduced for medical use in 1997. It was the first antiestrogen to be introduced since tamoxifen in 1978. It is available as a generic medication in the United States. Medical uses
Toremifene is approved for the treatment of metastatic breast cancer in postmenopausal women with estrogen receptor-positive or unknown-status tumors. This is its only approved use in the United States. It shows equivalent effectiveness to tamoxifen for this indication. Toremifene has been found to be effective in the treatment of breast pain and may be a more effective medication than tamoxifen for this indication. It also has superior effects on bone mineral density and lipid profile, including levels of cholesterol and triglycerides, compared to tamoxifen.
The apparent volume of distribution of toremifene ranged from 457 to 958 L.

Metabolism
Toremifene is metabolized in the liver primarily by CYP3A4 and then undergoes secondary hydroxylation. The metabolites of toremifene include N-desmethyltoremifene, 4-hydroxytoremifene, and 4-hydroxy-N-desmethyltoremifene, among others. Ospemifene (deaminohydroxytoremifene) is also a major metabolite of toremifene. Elimination
The elimination half-life of toremifene is 3 to 7 days in healthy individuals. In people with impaired liver function, the half-life is 11 days. The elimination half-lives of the metabolites of toremifene are 5 to 21 days for N-desmethyltoremifene, 5 days for 4-hydroxytoremifene, and 4 days for ospemifene. The long elimination half-lives of toremifene and its metabolites are thought to be due to enterohepatic recirculation and high plasma protein binding. Toremifene is eliminated 70% in the feces, as metabolites. Chemistry
Toremifene, also known as 4-chlorotamoxifen, is a derivative of triphenylethylene and a close analogue of tamoxifen. It is also closely related to afimoxifene (4-hydroxytamoxifen) and ospemifene (deaminohydroxytoremifene). History
Toremifene was introduced in the United States in 1997. It was the first antiestrogen to be introduced in this country since tamoxifen in 1978. Society and culture
Generic names
Toremifene is the generic name of the drug and its INN and BAN, while toremifene citrate is its USAN and JAN and torémifène is its DCF. Brand names
Toremifene is marketed almost exclusively under the brand name Fareston. Availability
Toremifene is marketed widely throughout the world and is available in the United States, the United Kingdom, Ireland, many other European countries, South Africa, Australia, New Zealand, and elsewhere throughout the world.