Indications for FARESTON:
Metastatic breast cancer in postmenopausal women with estrogen-receptor positive or unknown tumors.
60mg once daily. Continue until disease progression is observed.
Congenital/acquired QT prolongation. Uncorrected hypokalemia or hypomagnesemia.
Avoid in long QT syndrome. CHF. Hepatic impairment. Electrolyte abnormalities. Correct hypokalemia or hypomagnesemia prior to initiation; monitor periodically during therapy. Pre-existing endometrial hyperplasia; long-term therapy not established. Do baseline and annual gynecological exam; esp. monitor those at high risk of endometrial cancer. History of thromboembolic disease: not recommended. Bone metastases; monitor for hypercalcemia during first weeks of treatment, discontinue if severe. Leukopenia, thrombocytopenia; obtain leukocyte and platelet counts. Monitor CBCs, ECGs, calcium levels, liver function tests periodically. Pregnancy (Cat.D). Females of reproductive potential should use effective non-hormonal contraception. Nursing mothers: not recommended.
Caution with drugs that decrease renal calcium excretions (eg, thiazide diuretics). Avoid concomitant with drugs that prolong QT interval including Class 1A (eg, quinidine, procainamide, disopyramide) and Class III (eg, amiodarone, sotalol, ibutilide, dofetilide) antiarrhythmics, certain antipsychotics (eg, thioridazine, haloperidol), certain antidepressants (eg, venlafaxine, amitriptyline), certain antibiotics (eg, erythromycin, clarithromycin, levofloxacin, ofloxacin), certain anti-emetics (eg, ondansetron, granisetron); if needed, interrupt toremifene therapy; if interruption not possible, then monitor closely. Potentiated by strong CYP3A4 inhibitors (eg, ketoconazole, itraconazole, clarithromycin, atazanavir, indinavir, nefazodone, nelfinavir, ritonavir, saquinavir, telithromycin, voriconazole). Avoid grapefruit juice. Antagonized by strong CYP3A4 inducers (eg, dexamethasone, phenobarbital, phenytoin, carbamazepine, rifampin, rifabutin, St. John's Wort). Caution with concomitant CYP2C9 substrates with a narrow therapeutic index (eg, warfarin, phenytoin); monitor.
Hot flashes, sweating, nausea, vaginal discharge, dizziness, edema, vomiting, vaginal bleeding; Torsade de pointes, hepatotoxicity, hypercalcemia, tumor flare, endometrial hyperplasia; rare: leukopenia, thrombocytopenia.