Tamoxifen

Tamoxifen has mixed estrogenic antagonist and agonist properties. Tamoxifen binds to estrogen receptors (ER) and induces conformational changes in the receptor. For example, tamoxifen stimulates ER in bone and may actually prevent postmenopausal osteoporosis and has antiestrogenic effects on breast tissue. The ability of tamoxifen and other drugs to produce both estrogenic and antiestrogenic affects is most likely due to interaction with other coactivators or corepressors in the tissue and binding with different estrogen receptors, ER-alpha or ER-beta. The tissue distribution of ER-alpha and ER-beta suggest different functions for these receptors.

Your health care provider needs to know if you have any of these conditions: blood clots; blood disease; cataracts or impaired eyesight; endometriosis; high calcium levels; high cholesterol; irregular menstrual cycles; liver disease; stroke; uterine fibroids; an unusual or allergic reaction to tamoxifen or other products; pregnant or trying to get pregnant; breast-feeding. You will need regular exams and blood work while taking this medication.

Because hepatotoxicity can rarely occur in patients treated with tamoxifen, liver function tests should be monitored periodically during tamoxifen therapy.

Please discuss with your healthcare provider.

What are some possible side effects of this medicine? Fatigue; hair loss, although uncommon and is usually mild; headache; hot flashes; impotence; nausea, vomiting (mild); vaginal discharge. This list may not describe all possible side effects. Call your health care provider immediately if you are experiencing any changes in vision (blurred vision); changes in your menstrual cycle; difficulty breathing or shortness of breath; difficulty walking or talking; new breast lumps; numbness; pelvic pain or pressure; redness, blistering, peeling or loosening of the skin, including inside the mouth; skin rash or itching (hives); sudden chest pain; swelling of lips, face, or tongue; swelling, pain or tenderness in your calf or leg; unusual bruising or bleeding; vaginal discharge that is bloody, brown, or rust; weakness; yellowing of the whites of the eyes or skin.

Store this medication at 68°F to 77°F (20°C to 25°C) and away from heat, moisture and light. Keep all medicine out of the reach of children. Throw away any unused medicine after the beyond use date. Do not flush unused medications or pour down a sink or drain.