estrogen receptor blockers

tamoxifen

therapeutic use

• Treats estrogen-receptor-positive (ER+) metastatic breast cancer

• Prevents occurrence of breast cancer in clients who were assigned female at birth and who are at high risk

adverse effect

• Gastrointestinal symptoms: nausea, vomiting

• Hot flashes • Retinopathy, cataracts, decreased visual acuity

• Risk for uterine cancer, endometrial hyperplasia (overgrowth of tissue that lines the uterus)

• Increased risk for thrombophlebitis, thromboembolism

interventions

• Monitor for gastrointestinal effects.

• Monitor for hot flashes.

• Monitor for visual disturbances.

• Assist with endometrial biopsies as needed.

• Monitor for leg pain, sudden chest pain or shortness of breath, or signs of stroke

administration

orally, once or twice daily

client instructions

• Report persistent nausea and vomiting to provider.

• Report severe hot flashes to provider.

• Report blurred vision or decreased visual acuity.

• Have regular ophthalmic examinations while taking tamoxifen.

• Report abnormal menstrual bleeding to provider.

• Report leg pain or swelling; immediately report sudden chest pain or shortness of breath, weakness on one side of the body.

contraindications

• Pregnancy risk category D (1st trimester especially), lactation

• Anticoagulant therapy

• History of thrombocytopenia

• Preexisting endometrial hyperplasia

precautions

• Visual disturbances, cataracts

• Bone marrow suppression

• Hypercalcemia

• High blood cholesterol

• Ductal carcinoma in situ

interactions

• Estrogens may decrease effectiveness of concurrently administered tamoxifen.

• Blood levels are increased by bromocriptine.

• May increase the anticoagulant effect of warfarin.

• Other anticancer medications may increase risk for thromboembolism with tamoxifen.

major medication under estrogen receptor blockers

tamoxifen