Trade Names:Soltamox- Oral solution 10 mg per 5 mL
Trade Names:Tamoxifen Citrate- Tablets 10 mg- Tablets 20 mgApo-Tamox (Canada)Gen-Tamoxifen (Canada)Nolvadex-D (Canada)Tamofen (Canada)
A nonsteroidal agent with antiestrogenic properties.
Tamoxifen C max is 40 ng/mL (range, 35 to 45 ng/mL), T max is approximately 5 h after dosing, and steady state is achieved in about 4 wk.
Tamoxifen is extensively metabolized. The major metabolite is N-desmethyl tamoxifen. It is a substrate of CYP450 3A, 2C9, 2D6, and an inhibitor of P-glycoprotein.
Tamoxifen t ½ is 5 to 7 days; 65% of a dose is excreted over a 2-wk period, with fecal excretion as the primary route of elimination.
The effects of reduced liver function have not been determined.
Adjuvant treatment of breast carcinoma in women; metastatic breast carcinoma in men and women; reduction in risk of breast cancer in high-risk women; lower risk of invasive breast cancer in women with ductal carcinoma in situ (DCIS).
Ovulation stimulation in specially selected anovulatory women desiring pregnancy; management and treatment of some types of mastalgia (eg, cyclical); malignant carcinoid tumor and carcinoid syndrome; migraine associated with menstruation; metastatic malignant melanoma; oligozoospermia; McCune-Albright syndrome in female pediatric patients (in combination with other agents); metastatic melanoma; desmoid tumors; symptomatic gynecomastia.
Hypersensitivity to drug; women who require concomitant coumarin-type anticoagulant therapy; women with a history of deep vein thrombosis or pulmonary embolus.
PO 20 to 40 mg daily.DCIS, Reduction in Breast Cancer Incidence in High-Risk WomenAdults
PO 20 mg daily for 5 yr.
Do not store oral solution above 77°F. Do not refrigerate or freeze. To protect from light, store in original package. Use within 3 mo of opening. Store tablets at 68° to 77°F. Dispense in well-closed, light-resistant containers.
Tamoxifen concentrations may be reduced.Anastrozole
Plasma concentrations of anastrozole may be decreased. Do not coadminister.Bromocriptine
Tamoxifen concentrations may be increased.Cytotoxic agents
Increased risk of thromboembolic events.Letrozole
Plasma concentrations may be decreased by tamoxifen, reducing the therapeutic effect.Rifamycins (eg, rifampin)
Tamoxifen plasma levels may be reduced, decreasing the antiestrogenic effect.Warfarin
Increased hypoprothrombinemic effect.
T 4 elevations. Variations in the karyopyknotic index on vaginal smears and various degrees of estrogen effect on Pap smears.
Vasodilation (41%); hypertension (11%); ischemic cerebrovascular events, ischemic CV disease (3%).
Asthenia/fatigue, mood disturbances (18%); depression (12%); insomnia (9%); dizziness, headache (8%); anxiety (6%); paresthesia (5%); fatigue (4%).
Flushing (80%); skin changes (19%); rash (13%); sweating (6%); alopecia (5%); bullous pemphigoid, erythema multiforme, Stevens-Johnson syndrome (postmarketing).
Pharyngitis (14%); cataract (7%).
Nausea (26%); vomiting (12%); constipation (8%); diarrhea (7%); dyspepsia (6%); GI disorder (5%); anorexia (1%).
Vaginal discharge (55%); irregular menses (25%); amenorrhea, vaginal bleeding (23%); altered menses (13%); UTI (10%); leucorrhea, oligomenorrhea (9%); breast pain, menstrual disorder, vaginal hemorrhage (6%); breast neoplasm, vaginitis, vulvovaginitis (5%); ovarian cysts (3%), endometrial cancer (1%).
Lymphedema (11%); anemia, venous thromboembolic events (5%); deep venous thromboembolic events, thrombocytopenia (2%).
Increased AST (5%); increased bilirubin, increased creatinine (2%); elevated triglycerides in some cases with pancreatitis (postmarketing).
Fluid retention (32%); weight loss (23%); peripheral edema (11%); weight gain (9%); hypercholesterolemia (4%).
Arthritis (14%); arthralgia (11%); back pain (10%); fracture, osteoporosis (7%); bone pain (6%); arthrosis, joint disorder, myalgia (5%); musculoskeletal pain (3%).
Cough (9%); dyspnea (8%), bronchitis, sinusitis (5%); interstitial pneumonitis (postmarketing).
Pain (16%); accidental injury (10%); abdominal pain, infection (9%); flu syndrome (6%); chest pain, cyst, neoplasm (5%); edema (4%); abdominal cramps (1%); hypersensitivity, including angioedema (postmarketing).
Uterine malignancies, stroke, and pulmonary embolism have been reported with use in risk reduction setting (women with DCIS and women at high risk for breast cancer); some were fatal. Patient counseling in above patient groups may be necessary. Benefits outweigh risk in women with diagnosed breast cancer.
Perform gynecological examinations annually. Obtain periodic CBC, including platelet counts, and periodic LFTs. Periodic monitoring of plasma triglycerides and cholesterol may be indicated in patients with preexisting hyperlipidemias.
Category D .
Safety and efficacy in children have not been established.
Increased bone pain, tumor pain, and local disease flare are sometimes associated with a good tumor response shortly after starting tamoxifen, and generally subside rapidly.
Thrombocytopenia, leukopenia, and neutropenia and/or pancytopenia have occurred.
Changes in liver enzyme levels may occur.
If occurs, institute appropriate measures and, if severe, discontinue use.
An increased incidence of endometrial changes, including hyperplasia and polyps, have been reported. Endometriosis and uterine fibroids have been reported.
Secondary primary tumors, occurring at sites other than the endometrium, were reported following treatment of breast cancer with tamoxifen.
Deep vein thrombosis and pulmonary embolism have occurred.
Visual disturbances, including corneal changes, cataracts, the need for cataract surgery, decrement in color vision perception, retinal vein thrombosis, and retinopathy, have occurred with use.
Convulsions, neurotoxicity, QT interval changes.
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