Toremifene

Toremifene is a selective estrogen receptor modulator (SERM) used in the management of metastatic breast cancer in postmenopausal women. It is a derivative of triphenylethylene and is administered as the citrate salt.

Mechanism of action: Toremifene binds to estrogen receptors and acts as an antagonist in breast tissue, inhibiting estrogen-driven tumor growth, while exerting partial agonist effects in other tissues such as bone and lipid metabolism. This tissue-selective activity characterizes the SERM class.

Administration and pharmacokinetics: Toremifene is taken orally and undergoes extensive hepatic metabolism with active metabolites. It has a relatively long elimination half-life, which can lead to accumulation with repeated dosing.

Safety and adverse effects: Common effects include hot flashes, sweating, nausea, vomiting, vaginal discharge or bleeding, edema, and weight changes. Thromboembolic events and endometrial changes have been reported with SERMs. Toremifene should be avoided in pregnancy, and potential drug interactions with hepatic enzymes (such as CYP enzymes) may alter its levels. As with other SERMs, monitoring for cardiovascular and gynecological side effects is advised.