tamoxifen, Nolvadex (cont.)

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Medical and Pharmacy Editor:

DOSING: The dose for metastatic breast cancer treatment, DCIS, and prevention of breast cancer is 10 mg twice daily or 20 mg once daily for 5 years. The dose for stimulation of ovulation is 5-40 mg twice daily for 4 days. Tamoxifen can be taken with food.

DRUG INTERACTIONS: Tamoxifen increases the blood thinning effect of warfarin (Coumadin) and reduces blood levels of letrozole (Femara) and anastrozole (Arimidex). Phenobarbitol and rifampin may reduce blood levels of tamoxifen by increasing the breadkdown of tamoxifen.

PREGNANCY: Tamoxifen should not be used during pregnancy because it can harm the fetus.

NURSING MOTHERS: It is not known whether tamoxifen is excreted in breast milk. Tamoxifen causes a reduction in milk production. Women taking tamoxifen should not breastfeed.

SIDE EFFECTS: The most common side effects associated of tamoxifen are hot flashes, weight gain, abnormal or absence of menstrual periods, vaginal discharge, and nausea. Cough, fatigue, fluid retention, bone pain, cataracts, and depression also occur. Tamoxifen is associated with blood clots leading to deep vein thrombosis and pulmonary embolism. Tamoxifen can cause abnormalities of liver tests, reduced white blood cells, red blood cells, and platelets. Reduced platelets can lead to bleeding. Patients should keep appointments for blood work to monitor for these side effects. Patients should report any suspected side effects immediately, especially bleeding and yellowing of the skin.

Reference: FDA Prescribing Information


Last Editorial Review: 3/2/2012



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