Many people are able to use estrogen blockers without experiencing significant side effects, although any new or bothersome symptoms that develop after beginning treatment with this type of medication should be discussed with the prescribing physician. Some of the most common side effects of these substances include dizziness, nausea, and hot flashes. Additional side effects of these drugs may include weight gain, night sweats, and changes in vaginal discharge. More serious side effects of estrogen blockers, especially when used for prolonged periods of time, may include the development of blood clots, allergic reactions, or an increased risk of developing cancer of the reproductive organs.
Most side effects of estrogen blockers are relatively mild and may decrease over time as the body adjusts to the medication. Mild dizziness is a common complaint, but if this symptom becomes severe or is accompanied by a headache, a doctor should be consulted for further evaluation. If nausea develops when using this type of medication, it may help to eat a meal or drink a glass of milk before taking the drug.
Hot flashes, night sweats, and other menopause-like symptoms may develop when taking estrogen blockers. Bone or muscle pain, weight gain, and fatigue have been reported by those taking these medications. There may be an increase or a decrease in vaginal secretions by those using this type of drug. While most of these symptoms are mild in nature, dosage adjustments may sometimes be possible if these side effects become particularly bothersome.
Prolonged use of estrogen blockers increases the risks of developing serious side effects or potentially fatal complications. Blood clots may develop at any time during treatment, but the risk dramatically increases with extended use of these drugs. A form of bone loss known as osteoporosis may also occur, leading to a higher chance of fractures. Estrogen blockers may increase the risks of developing breast cancer, ovarian cancer, or other cancers affecting the reproductive system.
Allergic reactions to estrogen blockers are uncommon, although they are possible, even if the medications have been well tolerated in the past. Mild allergy symptoms may include a mild skin rash or itching. A potentially life-threatening type of allergic reaction known as anaphylaxis may cause symptoms such as swelling of the face or throat, chest pain, or difficulty breathing. These symptoms should be treated as a medical emergency, and hospital admission is often required in order to stabilize the health of the patient.