Kessar (Tamoxifen Citrate)

Tamoxifen citrate is a SERM used in the management of estrogen‑driven breast cancer and related risk scenarios.

• Adjuvant breast cancer: improves disease‑free survival after surgery in estrogen receptor‑positive patients.
• Metastatic breast cancer: slows disease progression in advanced hormone‑sensitive tumors.
• High‑risk women: lowers the incidence of invasive breast cancer in women with a strong family or genetic predisposition.

• Tamoxifen citrate binds competitively to estrogen receptors in breast tissue, blocking estrogen‑mediated cellular proliferation. In bone and uterine tissue it exhibits partial agonist activity, preserving bone density while exerting a mixed effect on the uterus. This selective modulation disrupts the growth signal cascade in estrogen‑dependent tumors, leading to cell cycle arrest and apoptosis.

Tamoxifen citrate may cause a range of adverse reactions that vary in frequency and severity.

Common Side Effects

• Hot flashes: transient episodes of warmth and sweating.
• Nausea: mild to moderate stomach upset.
• Fatigue: persistent tiredness not relieved by rest.
• Vaginal discharge or dryness: changes in genital secretions.
• Menstrual irregularities: altered cycle length or flow.
• Weight gain: modest increase in body weight.

Serious or Rare Side Effects

• Deep vein thrombosis or pulmonary embolism: signs of clot formation.
• Endometrial cancer: abnormal uterine bleeding.
• Liver toxicity: jaundice or elevated liver enzymes.
• Visual disturbances: blurred vision or retinal changes.
• Severe allergic reaction: rash, swelling, or breathing difficulty.

Before initiating tamoxifen citrate therapy, consider the following safety measures.

• Pregnancy testing: confirm non‑pregnant status before starting treatment.
• Thromboembolic risk: assess personal or family history of clotting disorders.
• Liver function: obtain baseline liver enzyme tests and monitor periodically.
• Ocular health: schedule regular eye examinations for patients with visual symptoms.
• Drug interactions: review concomitant medications for potential CYP2D6 inhibitors.
• Store at ambient temperature: keep below 25 °C in the original container, protect from moisture and direct sunlight.

Tamoxifen citrate can interact with several medicines, altering its effectiveness or safety profile.

Major Interactions (Avoid)

• Strong CYP2D6 inhibitors (e.g., paroxetine, fluoxetine): may reduce tamoxifen activation.
• Anticoagulants (e.g., warfarin): increased risk of bleeding.
• Hormonal contraceptives: may diminish contraceptive efficacy.

Moderate Interactions (Monitor Closely)

• SSRIs with weak CYP2D6 inhibition (e.g., sertraline): monitor therapeutic response.
• Aromatase inhibitors: overlapping endocrine effects require clinical judgment.
• Herbal supplements (e.g., St. John’s wort): may induce metabolism and lower drug levels.