TOREMIFENE CITRATE
| TOREMIFENE CITRATe (tor-em'i-feen ci'trate) Fareston Classifications: antineoplastic; hormone, antiestrogen; Therapeutic: antineoplastic; antiestrogen Prototype: Tamoxifen Pregnancy Category: D |
Availability
60 mg tablets
Action
Nonsteroidal antiestrogen chemical derivative of tamoxifen. Antitumor activity thought to be due to ability to compete with estrogen for binding sites in the cancer cells.
Therapeutic Effect
Depresses growth in estrogen receptor–positive tumors in postmenopausal women.
Uses
Metastatic breast cancer in postmenopausal women who are estrogen receptor positive.
Contraindications
Hypersensitivity to toremifene; history of thromboembolic disease; pregnancy (category D); lactation.
Cautious Use
Preexisting endometrial hyperplasia; bone metastases (may result in hypercalcemia); geriatric patients; leukopenia and thrombocytopenia; liver disease; history of thrombolytic disease.
Route & Dosage
| Breast Cancer Adult: PO 60 mg q.d. |
Administration
Oral- Withhold drug and notify physician if severe hypercalcemia develops.
- Store at 15°–30° C (59°–86° F) in a tightly closed container and protect from light.
Adverse Effects (≥1%)
Body as a Whole: Hot flashes, sweating, edema. CNS: Dizziness. GI: Nausea, vomiting, abnormal liver function tests. Respiratory: Pulmonary embolism. Urogenital: Vaginal discharge, vaginal bleeding. Special Senses: Cataracts, dry eyes, corneal keratopathy.Interactions
Drug: thiazide diuretics increase risk of hypercalcemia; increased PT on warfarin; carbamazepine, phenobarbital, phenytoin may increase toremifene metabolism.Pharmacokinetics
Absorption: Rapidly absorbed from GI tract. Peak: 3 h. Distribution: >99% protein bound; crosses placenta. Metabolism: In liver by cytochrome P450 3A4. Elimination: Primarily in feces. Half-Life: 5 d.Nursing Implications
Assessment & Drug Effects
- Lab tests: Periodically monitor CBC with differential, serum calcium, liver and kidney functions.
- Monitor patients carefully with bone metastases or those on drugs that decrease calcium excretion (e.g., thiazide diuretics) for S&S of hypercalcemia (see Appendix F).
- Monitor PT and INR carefully when given concurrently with warfarin.
Patient & Family Education
- Report to physician promptly any of the following: Unexplained weakness or fatigue, musculoskeletal pain or calf pain and tenderness, sudden chest pain, vaginal bleeding.
- Schedule periodic eye exams with long-term therapy.
Common adverse effects in italic, life-threatening effects underlined; generic names in bold; classifications in SMALL CAPS; 
Canadian drug name; 
Prototype drug