Indications

Tamona (Tamoxifen) is indicated for the treatment of:

• Breast cancer
• Anovulatory Infertility

Pharmacology

Tamoxifen is a non-steroidal drug that exhibits both oestrogen antagonist and oestrogen agonist (estrogen-like) effects in different tissues. In breast cancer, it primarily acts as an anti-oestrogen by preventing oestrogen from binding to its receptor on the tumour cells. It also helps to maintain bone mineral density in post-menopausal women.

Dosage & Administration

• Breast Cancer: 20 mg daily.
• Anovulatory Infertility:
  • Initial dose: 20 mg daily on days 2, 3, 4, and 5 of the menstrual cycle.
  • If necessary, the dose may be increased to 40 mg, and then 80 mg for subsequent courses.
  • For irregular cycles, the initial course can start on any day, with the next course 45 days later or on day 2 of menstruation.

Interaction

• Coumarin Anticoagulants: Tamona may significantly increase the anticoagulant effect; careful monitoring is recommended.
• Cytotoxic Agents: Combining Tamona with cytotoxic agents increases the risk of thromboembolic events (blood clots).

Contraindications

Tamoxifen must not be administered during pregnancy. It is also contraindicated in patients with a known hypersensitivity to the product or any of its ingredients.

Side Effects

Side effects can be related to the drug's oestrogen-like action or be more general:

• Pharmacological: Hot flushes, vaginal bleeding, vaginal discharge, pruritus vulvae (vaginal itching), and tumour flare.
• General: Gastrointestinal intolerance, headache, light-headedness, fluid retention, and hair loss (alopecia).
• Serious/Rare: Skin rashes (including Stevens-Johnson syndrome), hypersensitivity reactions, hypercalcaemia (in patients with bony metastases), deep vein thrombosis, pulmonary embolism, visual disturbances (corneal changes, retinopathy), cataracts, uterine fibroids, and severe liver abnormalities (fatty liver, hepatitis).
• Blood: Falls in platelet count and leucopenia have been reported.

Pregnancy & Lactation

• Pregnancy: Tamoxifen is contraindicated during pregnancy. Women must be advised to use barrier or nonhormonal contraception during treatment and for two months after stopping therapy. Premenopausal patients must be examined to exclude pregnancy before starting treatment.
• Lactation: It is not known if Tamoxifen is excreted in human milk, so it is not recommended during lactation.

Precautions & Warnings

• Tamona can suppress menstruation in some premenopausal women.
• An increased incidence of endometrial cancer has been reported; patients with abnormal gynaecological symptoms, especially vaginal bleeding, should be promptly investigated.
• Patients on or previously treated with Tamona may have an increased risk of second primary tumours, though a causal link is unestablished.

Therapeutic Class

Hormonal Chemotherapy.

Storage Conditions

Store between 20-25°C. Protect from light.