Tamoxifen is the oldest selective estrogen receptor modulator (SERM). Since its approval by the FDA in 1998, it has become one of the most commonly prescribed medication for millions of people in the prevention of breast cancer recurrence. Tamoxifen is primarily used to treat:
- Men and women diagnosed with estrogen receptor-positive, early-stage breast cancer after surgery, chemotherapy or radiation
- Men and women diagnosed with advanced-stage or metastatic hormone-receptor-positive disease
- Help shrink a large tumor before surgery in women (can help them avoid having a mastectomy)
- Slow down the growth of metastatic breast cancer or breast cancer that has spread or come back
- Stimulate ovulation in women who can’t tolerate Clomiphene
Tamoxifen is a first choice medication against breast cancer in women who haven’t gone yet through menopause. It is still an excellent choice for postmenopausal women who can’t tolerate aromatase inhibitors. Most women take Tamoxifen for five years following chemotherapy, surgery or radiation to reduce the risk of breast cancer from coming back. Some women switch to different hormonal therapy after using Tamoxifen for two to three years. It also reduces the risk of getting cancer in the other breast. When used approximately, Tamoxifen can reduce the risk of breast cancer from developing in the other breast by 50%. It may reduce your risk of estrogen receptor-positive breast cancer recurrence by half. This drug continues to have this benefit even after you stop taking it.
Tamoxifen is an anti-estrogen type of drug that works by blocking the estrogen receptors. Most breast cancer cells (estrogen receptor-positive cancer cells) fed on estrogen. The estrogen binds to the protein on the surface of the cancer cells and signals the cells to divide and grow in abnormal rate. Tamoxifen blocks the effect of estrogen in the receptor cells essentially starving the cancer cells, thus stop the cancer cells from growing.
In the treatment of infertility, this pill stimulates ovulation to women who can’t tolerate Clomiphene by blocking the estrogen receptors in the brain. This causes more luteinizing hormone (LH) and follicle-stimulating hormone (FSH) to be released by the pituitary gland. These two hormones stimulate the ovaries and cause the release of an egg.
As a SERM, this drug also offers other health benefits. It selectively either block or activates the action of estrogen on specific cells. Aside from blocking the action of estrogen on breast cells, Tamoxifen has estrogen-like effects on bone. It helps stop bone loss after menopause and lower the cholesterol level, specifically the LDL cholesterol.
How to Use It
- Breast cancer treatment- The duration of the treatment usually lasts from 5 to 10 years depending on the menopausal status of the patient. Newly diagnosed premenopausal and premenopausal women must take Tamoxifen for 5 years as their first hormonal therapy. After the initial treatment, another hormonal therapy is needed for 5 years. Based on evidence from two large randomized phase studies, a 10-year adjuvant treatment is associated with a smaller risk of breast cancer recurrence and reduced mortality rate compared with the 5-year treatment.
- Infertility –For the stimulation of ovulation in women, take Tamoxifen for a few days during your period.
Possible Side Effects of Tamoxifen
The most common side effects are:
- Loss of libido
- Mood swings
- Hot flashes
- Dry skin
- Hair thinning
Call your doctor right away if you will experience any of the following symptoms:
- Shortness of breath
- Chest pain
- Leg swelling or tenderness
- Sudden severe headache
- Abnormal vaginal discharge or bleeding
- Tingling or numbness in the arm. Leg or face
- Difficulty speaking
- Pressure and pain in the pelvis
Serious side effects that need immediate medical help are:
- Blood clot
- Endometrial cancer
What should I know before taking Tamoxifen?
Tamoxifen is not suitable for:
- Pregnant women
- People who are allergic to any of its ingredients
- Breastfeeding women
- Treating infertility among women with a family history of blood clots in the veins with no known cause.
- The risk of getting blood clot such as pulmonary embolism or deep vein thrombosis is higher in:
- People who are obese
- People who are having chemotherapy
- People with protein S deficiency or with a genetic disposition to blood clots
- Talk to your doctor about appropriate methods of contraception while taking Tamoxifen. It is very important that you don’t get pregnant while you take this medicine.
Getting the Best Result from Tamoxifen
- Take Tamoxifen only if the benefit to treat breast cancer outweigh any risk associated with the medicine.
- Your doctor may discontinue giving you Tamoxifen before any planned surgery if you are at a higher risk of a blood clot.
- If you get symptoms of a blood clot, stop taking this medication and contact your doctor right away. Symptoms of a blood clot include unusual swelling in one leg, stabbing pain in one leg, pain when coughing or breathing, sudden severe chest pain or sudden breathlessness.
- Avoid drinking alcoholic beverages if you find this medicine can make you feel dizzy, or if you are having hot flashes.
- The action of this drug on the endometrial tissue can raise the risk of uterine cancer for postmenopausal women but it is still rare.
- Tamoxifen may interact with both prescription and non-prescription drugs due to the way it metabolized. In this case, tell your doctor if you are using any other medications. In particular, anti-allergy drugs and anti-depressant drugs may reduce the effectiveness of this drug.
- Women who are pregnant should not use this due to a relatively high rate of birth defects. Women who are also trying to become pregnant should not use this Tamoxifen.
- Tamoxifen is a lifesaver for women with breast cancer. However, it should be use with caution and should be monitored by a physici