Tamoxifen

Indications

INDICATIONS AND USAGE Metastatic Breast Cancer Tamoxifen citrate tablets are effective in the treatment of metastatic breast cancer in women and men. In premenopausal women with metastatic breast cancer, tamoxifen citrate tablets are an alternative to oophorectomy or ovarian irradiation. Available evidence indicates that patients whose tumors are estrogen receptor positive are more likely to benefit from tamoxifen citrate tablet therapy. Adjuvant Treatment of Breast Cancer Tamoxifen citrate tablets are indicated for the treatment of node-positive breast cancer in postmenopausal women following total mastectomy or segmental mastectomy, axillary dissection, and breast irradiation. In some tamoxifen adjuvant studies, most of the benefit to date has been in the subgroup with four or more positive axillary nodes. Tamoxifen citrate tablets are indicated for the treatment of axillary node-negative breast cancer in women following total mastectomy or segmental mastectomy, axillary dissection, and breast irradiation.

Dosage and administration (summary)

DOSAGE AND ADMINISTRATION For patients with breast cancer, the recommended daily dose is 20 mg to 40 mg. Dosages greater than 20 mg per day should be given in divided doses (morning and evening). In three single agent adjuvant studies in women, one 10 mg tamoxifen citrate tablet was administered two (ECOG and NATO) or three (Toronto) times a day for 2 years. In the NSABP B-14 adjuvant study in women with node-negative breast cancer, one 10 mg tamoxifen citrate tablet was given twice a day for at least 5 years. Results of the B-14 study suggest that continuation of therapy beyond 5 years does not provide additional benefit (see CLINICAL PHARMACOLOGY ).

Contraindications

CONTRAINDICATIONS Tamoxifen citrate tablets are contraindicated in patients with known hypersensitivity to the drug or any of its ingredients. Reduction in Breast Cancer Incidence in High Risk Women and Women with DCIS Tamoxifen citrate tablets are contraindicated in women who require concomitant coumarin-type anticoagulant therapy or in women with a history of deep vein thrombosis or pulmonary embolus.

Warnings and precautions

WARNINGS Effects in Metastatic Breast Cancer Patients As with other additive hormonal therapy (estrogens and androgens), hypercalcemia has been reported in some breast cancer patients with bone metastases within a few weeks of starting treatment with tamoxifen. If hypercalcemia does occur, appropriate measures should be taken and, if severe, tamoxifen should be discontinued. Effects on the Uterus Endometrial Cancer and Uterine Sarcoma An increased incidence of uterine malignancies has been reported in association with tamoxifen treatment.

Pregnancy

Pregnancy Teratogenic Effects. Pregnancy Category D See WARNINGS .

Storage and supply

HOW SUPPLIED Tamoxifen Citrate Tablets, USP are containing tamoxifen as the citrate equivalent to 10 mg or 20 mg of tamoxifen. The 10 mg tablets are white, unscored, round tablets debossed with M on one side of the tablet and 144 on the other side.

Source: Tamoxifen Citrate (Tamoxifen Citrate) — US FDA prescribing information, 2021-07-02, DailyMed. Summarised and shortened; the full label governs. Iranian registration, indications and labelling may differ.