This is an automatically translated article.
Tamoxifen is an antineoplastic agent indicated for the endocrine treatment of estrogen-dependent breast cancer in women. In addition, Tamoxifen is also used in the treatment of anovulatory infertility. The following article provides readers with information about uses, dosages and precautions when using Tamoxifen.
What does Tamoxifen do?
Tamoxifen is a non-steroidal anti-estrogen, which inhibits the effects of endogenous estrogen. In breast cancer patients, Tamoxifen prevents estrogen from binding to estrogen receptors at the tumor. In addition, clinical reports found that, Tamoxifen reduced blood levels of total and LDL cholesterol, maintaining bone mineral density in postmenopausal women.
In addition, clinical results show that Tamoxifen is effective in tumors that are not related to the estrogen receptor, which indicates that the drug has a different mechanism of action.
Indications and contraindications of Tamoxifen 20mg
2.1. Indications Tamoxifen Endocrine treatment of estrogen-dependent breast cancer in women. Adjuvant treatment of estrogen-dependent breast cancer in women and adjuvant chemotherapy in selected cases. Tamoxifen is used as an adjunct to the treatment of women at high risk of recurrence after treatment for primary breast cancer. Stimulation of ovulation in infertile women due to anovulation. Primary prevention of breast cancer in women at moderate or high risk. Breast cancer in men. Albright syndrome. 2.2. Contraindications Allergy or hypersensitivity to Tamoxifen or any of its ingredients. Pregnant women. Concomitant use of Tamoxifen with Anastrozole. Porphyrin metabolism disorders. Treatment of Infertility: Tamoxifen should not be used in patients with a history of confirmed idiopathic venous thrombosis. Prevention of breast cancer: contraindicated in women with a history of deep vein thrombosis or pulmonary embolism, women requiring concomitant treatment with coumarin-type anticoagulants.
3. How to use Tamoxifen
3.1 Dosage for breast cancer treatment: Usual dose: 20mg/day, divided into 1-2 times. Up to 40mg/day can be used, but no additional benefit has been seen.
Treatment of infertility due to anovulation: Exclude the possibility of pregnancy in women prior to initiation of treatment and prior to initiation of the next course of treatment.
Women with regular menstrual periods but not ovulating: the first course of treatment is 20 mg/day, orally on the 2nd, 3rd, 4th and 5th days of the menstrual cycle. If no response (based on basal temperature or pre-ovulatory cervical mucus monitoring) use up to 40 mg then 80 mg/day during the next course of treatment. Women with irregular periods: the first course of treatment can be started on any day. If there is no evidence of ovulation, continue with a second course, starting 45 days later, with the dose of Tamoxifen increased as above. If the treatment responds, the next course begins on day 2 of the menstrual cycle. Use in children: The efficacy and safety of Tamoxifen in children have not been established, and therefore Tamoxifen is not recommended for use in children.
3.2 Tamoxifen 20mg overdose and management Symptoms of Tamoxifen overdose is acute neurotoxicity with symptoms such as fatigue, dizziness, tremor, hyperreflexia, and unsteadiness. These symptoms occurred within 3 to 5 days of starting Tamoxifen and resolved within 2 to 5 days of stopping the drug. Overdose symptoms occurred in patients receiving a loading dose greater than 400mg/m2/time and a maintenance dose of 150mg/m2/time, taken orally twice a day.
Currently there is no specific antidote for Tamoxifen overdose, treatment is mainly symptomatic supportive treatment.
4. Note when using Tamoxifen 20mg
During breast cancer treatment with Tamoxifen, some premenopausal patients may experience amenorrhea. Using Tamoxifen can cause leukopenia, thrombocytopenia. Tamoxifen use in premenopausal women requires careful monitoring because the drug induces ovulation. An increased frequency of endometrial disorders including hyperplasia, uterine polyps, endometrial cancer and uterine sarcoma has been reported in association with Tamoxifen. Monitor patients who have been taking Tamoxifen for unusual gynecological symptoms, especially vaginal bleeding, menstrual disorders, pain or heaviness in the lower abdomen. A second primary tumor occurring outside the endometrium and the other breast has been reported in clinical trials in breast cancer patients following Tamoxifen therapy. A causal relationship has not been established and the clinical significance of this observation remains unclear. Pregnancy: Tamoxifen is contraindicated in pregnant women. Spontaneous abortion, fetal malformation, and stillbirth have been reported in pregnant women taking Tamoxifen. Lactation: It is not known whether Tamoxifen is excreted in human milk, and it is not recommended to use Tamoxifen during lactation. The decision to discontinue breast-feeding or to discontinue tamoxifen depends on the importance of tamoxifen to the mother.
5. Undesirable effects of Tamoxifen 20mg
Tamoxifen is generally well tolerated, with adverse effects generally less common than with estrogens and androgens. Some common side effects when using Tamoxifen, accounting for 25% of people using the drug, such as hot flushes, nausea, vomiting. However, symptoms are rarely so severe that tamoxifen should be discontinued.
Common effects: Weight gain, hot flashes. Vaginal itching, redness and dryness of the skin, menstrual irregularities, vaginal bleeding, vaginal discharge. Increased pain and recurrent pain in the tumor or bone may be indicative of a response to tamoxifen. Uncommon: Hypercalcemia in patients with bone metastases. Dizziness, headache, depression, confusion, fatigue. Thrombocytopenia, leukopenia. Anorexia, hair loss, dermatitis. Fluid retention, thromboembolism, pulmonary embolism. Rare: Blurred vision and loss of vision, retinopathy and opacities, keratitis. Changes in blood lipids, changes in liver enzyme levels, cholestasis, hepatitis, liver necrosis. Endometriosis, uterine fibroids. In men using Tamoxifen: In this subject, when used, it can cause headache, skin rash, dry skin, hair loss, nausea, vomiting, bone pain, decreased sex drive.
During the use of Tamoxifen, the patient should periodically monitor the blood count, liver function, if the patient has a pre-existing increase in lipoproteins, the serum triglyceride and cholesterol should be monitored. If the patient experiences abnormal vision, the possible toxicity of Tamoxifen should be examined. In addition, if you have any symptoms such as irregular periods, abnormal vaginal bleeding, lower abdominal pain, you should inform your doctor about these effects.
6. Drug interactions
Coumarin-type anticoagulants: Tamoxifen may increase the anticoagulant effect. Cytotoxic agents for the treatment of breast cancer: Concomitant administration of Tamifine may increase the risk of thromboembolic events. Therefore, thromboprophylaxis should be considered in patients during combination chemotherapy. Rifampicin: Concomitant use may decrease Tamoxifen concentrations. Allopurinol increases the hepatotoxicity of Tamoxifen. Tamoxifen is an antineoplastic agent indicated for the endocrine treatment of estrogen-dependent breast cancer in women. In addition, Tamoxifen is also used in the treatment of anovulatory infertility. To ensure the effectiveness of treatment and avoid unwanted side effects, patients need to strictly follow the instructions of the doctor, professional pharmacist.
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