Tamoxifen (Nolvadex) - Uses, Dosage and Side Effects

Tamoxifen is an antagonist of the estrogen receptor in breast tissue via its active metabolite, hydroxytamoxifen. In other tissues such as the endometrium, it behaves as an agonist, hence tamoxifen may be characterized as a mixed agonist/antagonist. It has been the standard endocrine (anti-estrogen) therapy for hormone receptor-positive early breast cancer in pre-menopausal women.
Some breast cancer cells require estrogen to grow. Estrogen binds to and activates the estrogen receptor in these cells. Tamoxifen is metabolized into compounds that also bind to the estrogen receptor but do not activate it. Because of this competitive antagonism, tamoxifen acts like a key broken off in the lock that prevents any other key from being inserted, preventing estrogen from binding to its receptor. Hence breast cancer cell growth is blocked.
Tamoxifen is currently used for the treatment of both early and advanced ER+ (estrogen receptor positive) breast cancer in pre- and post-menopausal women. Tamoxifen is the most common hormone treatment for male breast cancer and is also approved by the FDA for the prevention of breast cancer in women at high risk of developing the disease. It has been further approved for the reduction of contralateral (in the opposite breast) cancer.
Tamoxifen is used to treat infertility in women with anovulatory disorders. A dose of 10-40 mg per day is administered in days 3-7 of a woman's cycle. In addition, a rare condition occasionally treated with tamoxifen is retroperitoneal fibrosis.
Tamoxifen is used to prevent estrogen related gynecomastia, resulting from elevated estrogenic levels in conjunction with steroid use. It is taken as a preventative measure in small doses, or used at the onset of any symptoms e.g. nipple soreness/sensitivity. Tamoxifen has been shown to be effective in the treatment of mania in patients with bipolar disorder by blocking protein kinase C (PKC), an enzyme that regulates neuron activity in the brain.

Side Effects of Tamoxifen (Nolvadex)

Adverse reactions to NOLVADEX are relatively mild and rarely severe enough to require discontinuation of treatment in breast cancer patients.
Flush, Amenorrhea, Altered Menses, Oligomenorrhea, Bone Pain, Menstrual Disorder, Nausea, Cough/Coughing, Edema, Fatigue, Muscoloskeletal Pain, Ovarian Cyst(s),Depression, Abdominal Cramps and Anorexia are some of the side efffects.

Tamoxifen (Nolvadex) - Dosage

Dosage will depend on the symptom being treated and will vary as per the idividual patient.
The normal adult starting dose that is commonly used is 20 mg when preventing breast cancer. The Tamoxifen (Generic Nolvadex) dosage can range from 20 to 40 mg a day when used to treat breast cancer.

Tamoxifen - Availability And Packaging

Tamoxifen is available as Nolvadex Tablets which is packaged in 10 mg tablets. It is also available under the brand names Istubal, and Valodex.

Additional Information

Additional Info: Prescribing Information