Tamoxifen is a medication used in the treatment of breast cancer for both women and men. As described by the doctors at the Mayo Clinic, it works by blocking estrogen in the body, the hormone largely responsible for the development of breast cancer. While many patients tolerate this medication well, there are a number of side effects that may occur. Some may even present themselves months or years after the treatment has taken place.
Side Effects That Subside
Tamoxifen generally produces side effects that subside once treatment progresses. These side effects may be easily prevented, or the severity reduced, and include the disruption of your menstrual cycle, the feeling of warmth in your body, a rattling when you breathe, changes in your skin, swelling of your extremities and limbs, weight gain or loss, decrease in urine production and flushing (a condition that causes a redness in your face, arms, neck and possibly your chest). It is also common to experience problems breathing while you are resting, and for women, a vaginal discharge that is white or brown in color.
More Common Side Effects
You may experience more common side effects that do not occur as frequently. They include bone or back pain, fatigue, muscle pain, indigestion, heartburn, insomnia, anemia, changes in your mood, hair loss, constipation or diarrhea, and headaches. You may also find yourself suffering from abdominal cramping, bleeding gums, a decreased libido, feelings of sadness, erectile dysfunction (inability to achieve or maintain an erection), itching in the genital area, irritability, problems concentrating and feelings of discouragement.
Side Effects to Report
The Mayo Clinic suggests calling your doctor immediately if you suffer from anxiety, blurred vision, chest pain, confusion, dizziness, rapid heartbeat, pain in your lower back or side, and pain or swelling in your legs (signs of a blood clot). You should also call if you have problems urinating, experience a shortness of breath or have problems breathing, begin sweating excessively, experience vaginal bleeding or develop jaundice (a yellowing of the skin or eyes).
Side Effects That Are Rare
Some patients experience rare side effects from taking tamoxifen. While MayoClinic.com states that the exact percentage is not known, these side effects include bloating, darkened urine, indigestion, joint or muscle pain, loss of appetite, eyes that are red or irritated, sore throat, vomiting, ulcers or sores that appear on your lips or the inside of your mouth, nausea and hive-like swelling on your sexual organs, face, tongue, hands, face, feet, eyelids and legs.
