Tamoxifen Pharmacology


About Tamoxifen
Mechanism of Action of Tamoxifen
Drug competes with estrogen in the body for estrogen receptor in breast tissue. Thus the transcription of estrogen responsive genes and growth of cancer cells associated with it inhibited.
Stimulation of Ovulation:Tamoxifen blocks the oestrogen receptors in the hypothalamus, it prevents the inhibitory action of oestrogen on release of FSH and LH and therefore the level of FSH and LH increase, which increases the chances of egg development and ovulation.

Pharmacokinets of Tamoxifen
Absorption- Well absorbed after oral administration.
Distribution-Drug and its metabolites distributed in the body.
Metabolism- Metabolized in the liver to its metabolites.N-desmethyl tamoxifen is its major metabolite.
Excretion- Excreted through urine.

Onset of Action for Tamoxifen
Several months after oral administration
Duration of Action for Tamoxifen
Half Life of Tamoxifen
Side Effects of Tamoxifen
1. Nausea
2. Vomiting
3. Diarrhea
4. Leucopenia
5. Thrombocytopenia
6. Elevated liver enzymes
7. Vaginal discharge
8. Irregular menses
9. Amenorrhea
10. Hypocalcaemia
11. Weight gain
12. Increased cholesterol level
13. Bone pain
14. Hot flushes
15. Fluid retention
16. Skin changes
17. Uterine fibroids
18. Hypertriglyceridaemia
19. Thromboembolism

Contra-indications of Tamoxifen
1. Hypersensitivity to the drug
2. Women who are taking coumarin type anticoagulants
3. History of deep vein thrombosis
4. Pulmonary edema
5. Porphyria
Special Precautions while taking Tamoxifen
1. Leucopenia
2. Thrombocytopenia
3. Monitor patients liver, renal and gynecological functions (in women) regularly.
Pregnancy Related Information
Old Age Related Information
Use with caution
Breast Feeding Related Information
Use with caution
Children Related Information
Indications for Tamoxifen
1. Breast cancer (advanced stage in men and in postmenopausal women)
2. Mastalgia
3. Stimulate ovulation
4. Gynecomastia
5. Retroperitoneal fibroid

Interactions for Tamoxifen
Oral anticoagulants: Significant increase in anticoagulant effect requiring careful monitoring of prothrombin time.
Bromocriptine: Serum tamoxifen levels are elevated.
Cyclophosphamide: Since tamoxifen is a potent inhibitor of cytochrome P450 oxidase it may affect metabolism and excretion of cyclophosphamide.
Typical Dosage for Tamoxifen
20-40mg/day in 2 divided doses.
Schedule of Tamoxifen
Storage Requirements for Tamoxifen
Stored at room temperature. Protect from excessive heat and light. Keep out of reach of children.
Effects of Missed Dosage of Tamoxifen
Take the missed dose as soon as noticed and if it is the time for next dose then skip the missed dose. Continue the regular schedule. Do not double the dose.
Effects of Overdose of Tamoxifen
Give symptomatic and supportive treatment.

Home Delivery for Tamoxifen in Your City

Medicine India is just a publishing medium for medicine related information and does not provide services or sales of medicines including tamoxifen.

However, we do publish a comprehensive directory of Pharmacies, Chemists and Druggists in cities all over India. You can use this directory to find the medicine stores in your city (or area) that provide home delivery services for tamoxifen and other medicines and health products. Home delivery services for tamoxifen may be free or they may cost you depending on the pharmacy and the minimum order requirements. It would be best to get this clarified while placing the order.

Please be aware that you should take tamoxifen only if a doctor has recommended or prescribed it. Some or all pharmacies who provide a home delivery service for medicines might insist on a prescription for tamoxifen before they complete the sale. You can get this information while placing the order for tamoxifen with the pharmacy.

Tamoxifen is a generic medicine name and there are several brands available for it. Some of the brands for tamoxifen might be better known than tamoxifen itself. If the pharmacy that's willing to deliver medicines to your home doesn't have tamoxifen in stock, you can ask for one of the branded alternatives for tamoxifen.