Tamoxifen is a prescription drug commonly used to treat certain types of cancer, particularly cancer of the breast. Both men and women may develop breast cancer, but the vast majority of cases diagnosed are in women. Exactly how tamoxifen works is not well understood, but it's believed to stop breast cancer because it blocks estrogen's effects. As with many drugs that have a profound effect on your body, tamoxifen may have serious side effects, some of which require immediate medical attention.
Menopausal
Some of the most common side effects of tamoxifen resemble menopause; these include hot flashes, vaginal dryness or discharge, mood swings, nausea and low libido. Tamoxifen may even induce you to enter menopause a little early if you were on the cusp of doing so already. Tamoxifen may also cause non-cancerous uterine changes and has been linked to an increased risk of uterine cancer.
Common
There are a host of relatively common side effects from tamoxifen that may not require emergency medical attention. Nonetheless, you should always inform your doctor about all bothersome side effects. If you're not sure about whether a given side effect requires fast medical attention, err on the side of caution.
These relatively minor side effects include: possible feelings of warmth, redness of the face, neck, arms and perhaps the upper chest, bone pain, stomach cramps, hair loss or hair thinning, erectile dysfunction (in men), skin rash and dryness, itching in the genital area, feeling discouraged, having trouble sleeping and having trouble concentrating.
Severe
Tamoxifen has some serious potential side effects; if you experience any of these severe symptoms, you should seek immediate medical attention. They include: a severe allergic reaction (which may include rash, hives, itching or swelling), dark urine, depression, pressure in the groin or pelvis area, abnormal menstrual periods or bloody discharge, pain in one or both legs, increasing or new unusual lumps in the breasts or elsewhere in the body, skin changes, sudden headache, chills, confusion, vision or speech changes, unusual bleeding or bruising and yellowing of the eyes or skin.
Other
As with all medications, you may experience side effects from tamoxifen that are not listed here. You may also experience symptoms that appear to be tamoxifen side effects but may in fact signal another condition entirely. This is one reason why it's important to keep your doctor informed about strange symptoms and side effects, even if you're not sure whether they are related to taking tamoxifen.
