Tamoxifen is used to treat breast cancer. This medicine lowers the chance of getting breast cancer for those who are at high risk of acquiring the disease.
This medicine may be used to treat other conditions as decided by your doctor.
Take Tamoxifen exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor.
You may take this medicine with or without food. Try to take it at the same time each day.
If you are taking an oral suspension, shake the bottle well before you take it to ensure that the liquid is evenly mixed. Use the measuring spoon or cup provided to measure out your prescribed dose.
Tamoxifen must be taken regularly for it to be effective. Continue taking this medicine even when you feel better. Do not stop taking it unless instructed by the doctor.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your normal dosing schedule.
DO NOT double a dose under any circumstances.
If you often forget to take your medicine, let your doctor and pharmacist know.
Alert your doctor if you have the following conditions:
- deep vein thrombosis (blood clot in the leg veins)
- pulmonary embolism (blood clot in the lungs)
as this medicine may not be suitable for you.
Do not take this medicine if you are pregnant or planning to have a baby soon. If you become pregnant while being treated with Tamoxifen, alert your doctor immediately. This medicine may cause harm to your unborn child. You must use proven birth control methods while taking Tamoxifen.
Do not breastfeed while being treated with this medicine.
DO NOT take Tamoxifen with medicines used to treat blood clot such as warfarin.
Inform your doctor if you have the following conditions:
- bone mineral density disorder
- hyperlipidaemia (excessive amount of fats in the blood)
Certain genetic traits can affect the effectiveness of Tamoxifen. Individuals who are poor metaboliser of CYP2D6 may respond poorer to this medicine. Although not routinely done, your doctor may advise you to take genetic testing to check if this medicine is best suited for you. If you know you have this gene type, inform your doctor.
For as long as you are taking Tamoxifen, you will need to have regular tests for the blood, liver function, cholesterol, eyes and bone mineral density to check your body's response to the medicine. Your doctor will advise you about how often you need to have these tests.
Tamoxifen may cause light headedness or some problems with your eyesight. If affected, do not drive or take part in any activity in which you need to be alert or need to see clearly.
Other side effects include any of the following: hot flushes, itch, rashes, dry skin, nausea and hair loss.
Some side effects may need immediate medical help. Alert your doctor quickly if you experience any of the following:
- unusual vaginal bleeding
- blocked blood vessel by a blood clot
Inform your doctor if any of these side effects do not go away or are severe, or if you experience other side effects.
DO NOT take Tamoxifen with blood thinning medicines such as warfarin.
Inform your doctor and pharmacist if you are taking any of these medicines:
- other medicines used to treat cancer e.g. aminoglutethimide, anastrozole, letrozole
- medicines for gout (uric acid disorder) e.g. allopurinol
- medicines to treat tuberculosis (TB) e.g. rifampicin
- medicines to treat depression e.g. bupropion, duloxetine, fluoxetine, paroxetine, sertraline
- medicines used in organ transplant or certain immune system disorders e.g. tacrolimus
- medicines for Parkinson's disease (disorder that affects movement of a person, causing symptoms such as tremors, muscle stiffness, slowed movement and impaired balance or walking) e.g. bromocriptine
- medicines for epilepsy (fits or seizures) e.g. phenobarbital
Inform your doctor if you are currently taking birth control pills as this can reduce the effectiveness of Tamoxifen. You should not stop or start any birth control pills without first informing your doctor. Ask your doctor about using non-hormonal birth control as an alternative while being treated with this medicine.
This list does not include all medicines that may interact with Tamoxifen.
Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicines, supplements and medicines that you buy without a prescription.
Avoid excessive consumption (more than 1 litre a day) of grapefruit juice.
Store in a cool, dry place away from the reach of children.
Medicines must not be used past the expiry date.
As this is a cancer medicine, always return any unused or expired tablets/solution to the clinic, hospital or pharmacy for disposal. Do not throw it away in the household waste.