Tamoxifen, a drug that blocks the effects of estrogen in the body, is used to treat breast cancer in both men and women. In addition, women over 35 who have a higher risk of developing breast cancer may also use Tamoxifen as a preventive medication, to reduce the risks of cancer, according to the Mayo Clinic. The risks associated with the drug include cataracts, increased cholesterol levels, blood clots or stroke. The benefits of using Tamoxifen include decreased risks of cancer. Positive results are noted in the Journal of the National Cancer Institute (JNCI).
Cataracts
Cataracts, an eye condition causing a cloudy area to form on the eye, is a possible side effect of Tamoxifen. With cataracts, loss of color intensity, double vision, trouble seeing at night and sensitivity in the eye are common. According to the national Library of Medicine, most individuals with the condition have similar changes in both eyes, though one may be more severe than the other. In addition, mild changes are often likely with cataracts.
More Serious Side Effects
More serious side effects like blood clots and stroke may occur with those taking Tamoxifen, particularly among those taking the drug for reducing the risks of breast cancer, according to the Mayo Clinic. However, these risks subside when treatment with Tamoxifen ends. JNCI noted some positive results.
Increased Cholesterol Levels
Another side effect related to Tamoxifen is increased cholesterol levels in the blood. Your doctor may monitor your cholesterol levels and suggest ways to help reduce cholesterol.
Benefits
While the above risks may seem serious, the benefits of Tamoxifen may outweigh the risks for some individuals. According to JNCI, the initial results of one study indicates the drug reduced the risks of invasive estrogen receptor (ER)--positive tumors by 31 percent in women whose risks for breast cancer were increased. Follow-up reports maintain the benefits of reduced cancer risks remained even after treatment with Tamoxifen ended, as higher instances of cancer were diagnosed in women who were treated with a placebo. In addition, the negative side effects associated with Tamoxifen abated when treatment ended.
