Sex hormones, such as estrogen, are naturally present in males and females. In some cases, it is important to reduce these hormones' activity for medical purposes. It is very difficult to eliminate hormones from the body, but it is possible to block the cells that respond to these hormone levels with particular compounds. Tamoxifen is one example of this type of compound.
Identification
Tamoxifen is a member of a class of drugs called antiestrogens. Antiestrogens are compounds used to block the effects of estrogen. Because estrogen can aggravate some medical conditions, such as breast cancer, drugs such as tamoxifen can be used to limit estrogen's effects.
Uses
Tamoxifen typically is used to treat or prevent breast cancer. Tamoxifen can be used in the treatment of metastatic breast cancer (breast cancer that has spread throughout the body) or as part of a chemotherapy and radiation regimen for early stages of breast cancer. It can also be given to women who are deemed "high risk" (due to their medical history, family history and age) for breast cancer to try to prevent the disease. In addition, tamoxifen can also be used to cause ovulation for women who are not producing eggs but wish to become pregnant, or to treat a condition in children known as McCune-Albright syndrome, which can cause early sexual development, bone disease and spots of hyperpigmentation on the skin.
Administration
Tamoxifen is typically given in tablet form. These tablets need to be taken whole (not crushed or chewed) with water once or twice a day (depending on the dosage). For breast cancer prevention, tamoxifen may need to be taken for five years. Otherwise, your physician will instruct you as to how long you will need to take tamoxifen. Tamoxifen is most effective when taken consistently, so it is important to not miss a dose.
Mild Side Effects
Because tamoxifen blocks the action of the sex hormone estrogen, it can cause a number of side effects, including hot flashes. Sexual side effects include loss of sex drive, difficulty in achieving orgasm and impotence. Tamoxifen can also cause nausea, constipation, weight loss, fatigue and headaches. Tamoxifen usage may also cause dizziness, depression and hair loss. When used to treat breast cancer, it can also cause pain and redness around the area of the tumor.
Serious Side Effects
Some of the side effects of tamoxifen are serious and require immediate medical attention if they occur. These include symptoms of liver failure, which cause jaundice (yellowing of the skin and eyes) and bleeding problems (easy bruising and excessive bleeding). Other serious side effects include problems with vision, a rash, swelling of the face and extremities (including hands, feet, and arms), and blisters. Finally, tamoxifen can cause excessive thirst and muscle weakness.
