Tamoxifen

• Some types of breast cancer in women and men
• Stimulate release of eggs from the ovary (ovulation) in females with who are problems (anovulation)
• Prevent development of breast cancer in high-risk patients (e.g. family history of breast cancer)

When should one not use Tamoxifen

• If you are allergic to Tamoxifen
• If you are taking Anastrozole
• If you or someone in your family has had blood clots due to unknown causes (idiopathic)
• If you have a history of blood clot formation in the legs or lungs (deep vein thrombosis or pulmonary embolism)
• If you are taking medicines used to prevent blood clots such as Warfarin
• If you are not sure, discuss to your doctor or pharmacist before taking Tamoxifen tablets

Common side effects of this drug are:

• Fluid retention
• Skin rash
• Hot flushes (feeling of heat and sweats)
• Vaginal bleeding or discharge
• Tiredness
• Uterine fibroids
• Anaemia (a blood problem which means you have too few red blood cells)
• Changes in vision due to cataracts or changes to the retina of your eye
• Increased amounts of fats in your blood (shown by blood tests)
• Allergic reactions
• Cataracts and eye problems
• Increased risk of blood clots (including clots in small vessels)
• Changes in the womb (including changes to its lining and benign growths)
• Headache
• Feeling light-headed
• Liver problems
• Loss of hair
• Muscle pain
• Sensory changes (including taste disturbances and numbness or tingling in the skin)
• Severe blood problems (reduced blood cell counts) - this can get you to bruise more easily, get serious infections or feel very tired or breathless (rare)
• Changes to the cornea of your eye (rare)
• Problems with the nerve that connects your retina to your brain (swelling of the optic nerve)
• Severe life-threatening liver diseases – include liver infections, liver cirrhosis, liver cell damage, reduced bile formation and complete liver failure (rare)
• Severe life-threatening allergic reactions (angioedema, vasculitis, Stevens-Johnsons syndrome, etc.)
• Suppression of menstruation (rare)
• Vaginal growths (polyps)
• Infections and increased thickness of lining of the uterus (endometrium)
• Other uncommon cancers (rare)

Other General Warnings

• You have delayed breast reconstruction operation (repeated procedure after the primary breast operation)
• Tamoxifen may increase the risk of the formation of blood clots
• Menstruation may be suppressed in some patients
• Changes in the lining (endometrium) of the uterus (increased thickness and unwanted growths)
• Cancerous growths (secondary tumors) at sites other than breast and lining of the uterus (endometrium)

How Does It Work?

• Estrogen dependent breast cancers are the most common type of breast cancers
• Tamoxifen blocks the uncontrolled breast growth due to signals from estrogen hormone and thus stops progression of breast cancer
• In females with ovulation problems (releasing eggs from ovaries between 10-15th day of a regular menstrual cycle)
• Tamoxifen acts on structures in the brain, regulates estrogen levels and causes release of the eggs (improving female fertility)

Interactions with other medicines

• Carbamazepine (used to treat seizures)
• Erythromycin (anti-bacterial)
• Amiodarone (used to treat irregular heartbeats)
• Warfarin (blood-thinning agent)
• Rifampicin (used to treat TB)
• Ritonavir (HIV medicine)
• Dexamethasone (steroid used to treat allergies, skin and joint diseases)
• Certain antidepressants (Paroxetine, Fluoxetine, Bupropion)
• Quinidine (used to treat irregular heartbeats)

Overdose

Missed a Dose