Tamoxifen is a drug used to prevent and treat breast cancer. Tamoxifen, sold under the brand name Nolvadex, interferes with estrogen production and usage and has been a staple in treating cancer in both men and women since the 1970s. The drug has been used primarily as a preventive medication since 1999 to treat women at risk for developing breast cancer. Although the National Cancer Institute reports that the benefits outweigh the risks, tamoxifen does carry the potential for serious side effects.
Blood Clots
Large clinical trials performed by the National Cancer Institute found that tamoxifen creates an increased risk of developing blood clots in a small number of cases. Women who are receiving chemotherapy for breast cancer are at a higher risk of getting blood clots that can lead to stroke. Blood clots typically form in the lungs or the legs.
Uterine Cancer
Women taking tamoxifen who still have a uterus are at an increased risk of developing uterine cancer, reports the National Cancer Institute. Both endometrial cancer and uterine sarcoma have been found in women taking tamoxifen. Studies showed women were likely to develop endometrial cancer in two out of 1,000 cases, while uterine sarcoma developed in one out of 1,000 taking the drug.
Cataracts
Older women taking tamoxifen can be exposed to a higher risk of developing cataracts, which is a clouding of the lens on the inside of the eye. Other eye diseases connected with tamoxifen usage include retinal changes and corneal scarring.
Menopause Symptoms
While tamoxifen does not trigger the onset of menopause in premenopausal women, it does create symptoms similar to the change of life. Hot flashes, night sweats and irregular menstrual cycles are common side effects of the drug, reports the Mayo Clinic. The ovaries continue to operate normally in most premenopausal women.
Physical Side Effects
The National Institutes of Health report that symptoms vary between patients and can cause temporary side effects or long-term health consequences. Among the physical side effects of tamoxifen are nausea, dizziness, headaches and constipation. Some women develop depression, loss of sexual desire and thinning hair. Weight loss, stomach cramps and fatigue may develop. Serious side effects should be reported to a physician immediately and include jaundice, fever, muscle weakness and swelling.
Birth Defects
Women who are pregnant or who are considering pregnancy should not take tamoxifen, because it has been shown to produce birth defects in animal studies, reports the National Cancer Institute.
