) (marketed as Nolvadex) is one of the most commonly used anti-estrogen breast cancer treatments in the world. The medications works by blocking estrogen receptors in estrogen receptor-positive (ER-Positive or ER+) cancer, which accounts for over 70% of breast cancer. Deprived of estrogen, cancer may fail to develop, grow or spread.
Most often tamoxifen is given to:
- Prevent the development of cancer in high-risk patients
- Inhibit growth or spread of existing cancer
- Prevent regrowth of cancer after surgery, chemotherapy or other treatments
Tamoxifen is used most commonly in women, both premenopausal and postmenopausal, though it also used in men and, rarely, children. It also serves other functions, though far less frequently, as a fertility treatment, to inhibit early puberty, in certain other cancers, and in treating a handful of other conditions. Effective Use of Tamoxifen
The medication comes in tablets of 10 to 20 mg, which should be swallowed whole without chewing, dissolving or splitting. The prescribed daily dosage will depend on the condition being treated as well as any other medications being taken at the same time.
If dosage exceeds 20 mg, or one tablet, the total daily dose is usually divided into two doses of equal strength. If taking a single tablet, it should be taken in the morning. If taking multiple tablets divided into two doses, they should be taken as close to 12 hours apart as possible. If an uneven amount of tablets are being divided, the higher number should be taken in the morning.
Ideally tablets are taken at the same time each day, to keep levels of the drug consistent in the body. Missed doses should be taken as soon as possible.
Treatment is likely to last 5 years or longer, and it is very common for other supplementary medications to be given along with tamoxifen during this time. Regular checkups are vital to ensure the medication is working as desired, adjust dosage strength if needed, and to check for developing adverse effects.
Some patients do not respond well to tamoxifen, either seeing little benefit or experiencing disruptive side effects. In these cases there are many similar medications available which may be more suitable; it is worth discussing alternative options with a doctor if tamoxifen doesn't seem to be providing benefits. Other Considerations
To ensure treatment goes smoothly there are a few things to keep in mind:
- Tamoxifen's estrogen-blocking properties may render hormonal birth control methods, such as pills, patches and some implants, ineffective. Alternative birth control methods should be used during treatment, and for several months after treatment stops.
- Women who are pregnant or breast feeding should not use tamoxifen; this medication may be quite harmful. Likewise, women who pregnant or nursing should not even handle tablets, as the medication is easily absorbed into the skin.
- The medication may cause inaccuracies in lab tests; be sure lab technicians are aware tamoxifen is being taken.
- Some patients, particularly those with existing cancer, may experience increased pain and even tumor growth shortly after treatment begins. Though it may be alarming, it is actually a sign the medication is working. Symptoms should diminish after a few days of treatment.
- Tamoxifen may cause easy bleeding. Be sure all doctors, dentists and other health care providers are aware the medication is being taken before undergoing any procedures.
Side effects, if experienced at all, often stop after a few days of treatment. The most common side effects are generally mild and not cause for alarm:
- Hot flashes
- Stomach upset
- Leg cramps
- Menstrual changes
- Loss of interest in sex
- Hair thinning
Patients with a history of blood clots or stroke, or who are taking blood thinners, should use tamoxifen with caution and receive regular checkups to monitor the medication's effect.