letrozole

Generic Name: letrozole (LET row zol)

Brand Names: Femara

What is letrozole?

Letrozole lowers estrogen levels in postmenopausal women, which may slow the growth of certain types of breast tumors that need estrogen to grow in the body.

Letrozole is used to treat breast cancer in postmenopausal women. It is often given to women who have been taking tamoxifen (Nolvadex, Soltamox) for 5 years.

Letrozole may also be used for purposes other than those listed here.

What is the most important information I should know about letrozole?

Before taking letrozole, tell your doctor if you have liver disease. You may need a dose adjustment or special tests to safely take this medication. Do not use this medication if you are pregnant. It could cause harm to the unborn baby. Use an effective form of birth control, and tell your doctor if you become pregnant during treatment.

Use this medication exactly as it was prescribed for you. Do not use it in larger doses or for longer than recommended by your doctor.

There may be other drugs that can affect letrozole. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

Stop using this medication and get emergency medical help if you think you have used too much medicine, or if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Less serious side effects are more likely, and you may have none at all. Talk to your doctor about any side effect that seems unusual or is especially bothersome.

What should I discuss with my healthcare provider before using letrozole?

You should not use this medication if you are allergic to letrozole, or if you have not gone completely through menopause. Before taking letrozole, tell your doctor if you have liver disease. You may need a dose adjustment or special tests to safely take this medication. FDA pregnancy category D: This medication can cause harm to an unborn baby. Do not use letrozole if you are pregnant. Tell your doctor if you become pregnant during treatment. Use an effective form of birth control while you are using this medication. It is not known whether letrozole passes into breast milk. Do not take letrozole if you are breast-feeding a baby.

How should I take letrozole?

Take letrozole exactly as it was prescribed for you. Do not take it in larger doses or for longer than recommended by your doctor.

Take each dose with a full glass (8 ounces) of water.

Letrozole is usually taken once a day. Follow your doctor's instructions.

Letrozole can be taken with or without food.

To be sure this medication is helping your condition, you will need to be tested on a regular basis. Your bone mineral density may also need to be checked. It is important that you not miss any scheduled visits to your doctor.

Store letrozole at room temperature away from moisture and heat.

See also: Letrozole dosage (in more detail)

What happens if I miss a dose?

Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and take the medicine at the next regularly scheduled time. Do not take extra medicine to make up the missed dose.

What happens if I overdose?

Seek emergency medical attention if you think you have used too much of this medicine.

An overdose of letrozole is not expected to produce life-threatening symptoms.

What should I avoid while taking letrozole?

Letrozole can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

Letrozole side effects

Stop using letrozole and get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Less serious side effects may include:

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  hot flashes, warmth or redness in your face or chest;

  
  


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  headache, muscle or joint pain;

  
  


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  night sweats;

  
  


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  weight gain;

  
  


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  fatigue, feeling weak;

  
  


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  nausea; or

  
  


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  swelling in your hands, ankles, or feet.

  
  

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

Letrozole Dosing Information

Usual Adult Dose for Breast Cancer:

For use as first-line treatment of postmenopausal women with hormone receptor positive or hormone receptor unknown locally advanced or metastatic breast cancer. Letrozole is also indicated for the treatment of advanced breast cancer in postmenopausal women with disease progression following antiestrogen therapy: 2.5 mg tablet orally administered once a day without regard to meals.

In patients with advanced disease, letrozole therapy should continue until tumor progression is evident.

Usual Adult Dose for Breast Cancer -- Adjuvant:

For use as extended adjuvant treatment of early breast cancer in postmenopausal women who have received 5 years of adjuvant tamoxifen therapy: 2.5 mg tablet orally administered once a day without regard to meals.

The optimal duration of treatment with letrozole is not known. Treatment should be discontinued if there is a tumor relapse.

What other drugs will affect letrozole?

There may be other drugs that can affect letrozole. Tell your doctor about all the prescription and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

More letrozole resources

• Letrozole Side Effects (in more detail)
• Letrozole Dosage
• Letrozole Use in Pregnancy & Breastfeeding
• Drug Images
• Letrozole Drug Interactions
• Letrozole Support Group
• 16 Reviews for Letrozole - Add your own review/rating

• letrozole Advanced Consumer (Micromedex) - Includes Dosage Information


• Letrozole Prescribing Information (FDA)


• Letrozole Professional Patient Advice (Wolters Kluwer)


• Letrozole Monograph (AHFS DI)


• Letrozole MedFacts Consumer Leaflet (Wolters Kluwer)


• Femara Prescribing Information (FDA)


• Femara Consumer Overview

Compare letrozole with other medications

• Breast Cancer
• Breast Cancer, Adjuvant
• Breast Cancer, Metastatic
• Female Infertility

Where can I get more information?

• Your pharmacist can provide more information about letrozole.

See also: letrozole side effects (in more detail)