Tamoxifen 10mg / 20mg

What is Tamoxifen?

Tamoxifen is a prescription medication used to treat and prevent hormone receptor-positive breast cancer. It belongs to a class of drugs known as selective estrogen receptor modulators (SERMs), which act by blocking estrogen in some tissues (like the breast) while mimicking estrogen in others (such as bones and the uterus).

Tamoxifen has been used for decades as a standard treatment for both early-stage and metastatic ER+ breast cancer in premenopausal and postmenopausal individuals. It’s also FDA-approved for reducing the risk of breast cancer in high-risk populations — including those with BRCA gene mutations or strong family histories of the disease.

This oral medication is typically taken once daily and is available in 10mg and 20mg tablets. Treatment duration varies depending on patient profile and disease severity, but most people take it for 5 to 10 years.

TrandFamilyStore offers tamoxifen through a structured telehealth program, ensuring patients receive personalized treatment plans, proper lab testing, and continuous monitoring during long-term use.

How It Works

Estrogen is a key hormone in the development of certain types of breast cancer. In ER+ tumors, estrogen binds to its receptor and promotes cell division and tumor growth. Tamoxifen works by competing with estrogen for these receptor sites in breast tissue, essentially blocking the hormone’s action at the cellular level.

Unlike aromatase inhibitors (which reduce estrogen production), tamoxifen does not lower estrogen levels — instead, it selectively blocks estrogen’s effects in the breast while maintaining its activity elsewhere. This means that in bones, tamoxifen may actually help preserve density, which is beneficial for postmenopausal individuals at risk of osteoporosis.

The drug’s active metabolite, endoxifen, is produced via the liver enzyme CYP2D6. Some medications — including certain antidepressants — can interfere with this conversion, reducing the drug’s effectiveness. For this reason, it’s important to disclose all medications you’re taking when starting tamoxifen.

TrandFamilyStore provides pharmacist and physician oversight to avoid harmful interactions and ensure tamoxifen is metabolized correctly.

Dosage Information

The standard tamoxifen dosage is 20mg taken orally once daily. Some treatment plans may involve 10mg twice daily, particularly for those experiencing side effects or when prescribed for fertility reasons. The dosage may vary based on age, menopausal status, treatment goals, and tolerance to side effects.

Indications:

• Early-stage breast cancer: 20mg/day for 5–10 years
• Metastatic breast cancer: dose varies with disease progression
• Breast cancer prevention: 20mg/day for 5 years in high-risk individuals
• Infertility (off-label): 10–40mg/day on days 3–7 of the cycle, under specialist care

Take tamoxifen at the same time daily, with or without food. If a dose is missed, take it as soon as remembered unless it's near the next dose. Do not double up.

TrandFamilyStore supports patients with tailored reminder systems and refill scheduling to maintain consistency throughout treatment.

Side Effects

Tamoxifen is generally well-tolerated, but side effects can vary in intensity. Most patients experience mild to moderate symptoms that improve over time. Common side effects include:

• Hot flashes or night sweats
• Vaginal discharge or dryness
• Fatigue or insomnia
• Headache
• Mood swings or irritability
• Menstrual irregularities

Less common but more serious side effects:

• Blood clots (DVT or pulmonary embolism)
• Stroke (rare)
• Uterine cancer (especially in postmenopausal women)
• Changes in vision or cataracts

Patients should promptly report any signs of leg swelling, shortness of breath, chest pain, or abnormal bleeding to their healthcare provider.

TrandFamilyStore encourages open communication throughout the course of therapy and offers symptom management strategies for common issues like hot flashes and vaginal dryness.

Warnings & Interactions

Tamoxifen is contraindicated in patients with a history of thromboembolic events, certain uterine abnormalities, or known hypersensitivity to the drug. Use is not advised during pregnancy or while breastfeeding.

Important precautions:

• Do not use tamoxifen during pregnancy. It may cause fetal harm. Use non-hormonal contraception throughout treatment and for 2 months after stopping.
• Monitor liver function if tamoxifen is taken long-term or with hepatically metabolized drugs.
• Inform your doctor if you take CYP2D6 inhibitors (like paroxetine or fluoxetine), as they can lower tamoxifen’s effectiveness.

Routine screenings — such as pelvic exams, mammograms, and possibly ophthalmic evaluations — are recommended during prolonged therapy.

TrandFamilyStore ensures all safety protocols are followed and reviews patient history in detail before prescribing.