Letrozole is a drug used to treat breast cancer in post-menopausal women. It is a type of hormone treatment known as an aromatase inhibitor.

Why have I been prescribed Femara?

Femara (Letrozole) is a drug used to treat breast cancer in post-menopausal women. It is a type of hormone treatment known as an aromatase inhibitor.

How does it work?

  • The female hormone oestrogen is involved in the stimulation of some breast cancers. This means that in these types of tumours oestrogen encourages the cancer cells to grow. When a woman has been through the menopause, oestrogen is produced in body tissues such as fatty tissue and the tumour itself. Femara works by stopping the production of oestrogen and so reducing the amount of oestrogen circulating around the body.

When and how do I take it?

Femara comes as a tablet that you take once a day. It is best to take it at the same time every day. If you miss a dose you don't need to take an extra dose the next day as the level of drug in your body will remain high from the previous day. It is important not to stop taking Femara without talking to your specialist first.

What’s the dose?

  • 2.5mg a day.

Could they interact with other tablets?

  • It is not advisable to take other drugs containing oestrogen, such as hormone replacement therapy (HRT), while you are taking Femara. 
  • There do not seem to be any other drugs that interfere with Femara and other medicines are not affected if you are taking Femara.

Herbal supplements should be used with caution and only after informing your doctor first.

What are the possible risks or side-effects?

More common side effects:

  • Aching or pain in the muscles and joints
  • loss of appetite or nausea. 

You may have menopausal symptoms such as:

You can do practical things to help yourself such as wearing cotton clothing and reducing your intake of caffeine and alcohol. Some people find complementary therapies helpful. You may also suffer from nausea or vomiting which will be helped by taking your tablet with food.

Less common side effects:

They are usually temporary, but you should tell your specialist if you experience any of these. Some women notice that their hair becomes thinner while taking Femara, although it is not usually noticeable to other people. Aromatase inhibitors may cause osteoporosis (bone weakening) when administered for a prolonged period. 

Other less common side effects include: 

  • perspiration
  • constipation
  • feeling in a low mood
  • weight gain may also occur in some women

Can I drink alcohol while taking it?

  • Femara may cause drowsiness or dizziness. These effects may be worse if you take it with alcohol.

What if I’m pregnant/breastfeeding?

Femara cannot be taken during pregnancy or breast feeding.

If you have any more questions please ask your Pharmacist.

Remember to keep all medicines out of reach of children
Please Note: 
We have made every effort to ensure that the content of this information sheet is correct at time of publish, but remember that information about drugs may change. This sheet does not list all the uses and side-effects associated with this drug. For full details please see the drug information leaflet which comes with your medicine. Your doctor will assess your medical circumstances and draw your attention to any information or side-effects which may be relevant in your particular case.








Health Reference: Breast Cancer