Drugs A - Z

Letrozole Oral tablet

An aromatase inhibitor - Certain types of breast cancer grow under the influence of estrogen

Generic Name: letrozole

Brand Names: Femara

What is this medicine?

LETROZOLE (LET roe zole) blocks the production of estrogen. Certain types of breast cancer grow under the influence of estrogen. Letrozole helps block tumor growth. This medicine is used to treat advanced breast cancer in postmenopausal women.

This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

What should I tell my health care provider before I take this medicine?

They need to know if you have any of these conditions:

How should I use this medicine?

Take this medicine by mouth with a glass of water. You may take it with or without food. Follow the directions on the prescription label. Take your medicine at regular intervals. Do not take your medicine more often than directed. Do not stop taking except on your doctor's advice.

Talk to your pediatrician regarding the use of this medicine in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.
NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medicine?

Do not take this medicine with any of the following medications:

This medicine may also interact with the following medications:

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

What should I watch for while using this medicine?

Visit your doctor or health care professional for regular check-ups to monitor your condition.

Do not use this drug if you are pregnant. Serious side effects to an unborn child are possible. Talk to your doctor or pharmacist for more information.

You may get drowsy or dizzy. Do not drive, use machinery, or do anything that needs mental alertness until you know how this medicine affects you. Do not stand or sit up quickly, especially if you are an older patient. This reduces the risk of dizzy or fainting spells.

What side effects may I notice from receiving this medicine?

Side effects that you should report to your doctor or health care professional as soon as possible:
  • allergic reactions like skin rash, itching, or hives
  • bone fracture
  • chest pain
  • difficulty breathing or shortness of breath
  • severe pain, swelling, warmth in the leg
  • unusually weak or tired
  • vaginal bleeding

Side effects that usually do not require medical attention (report to your doctor or health care professional if they continue or are bothersome):

  • bone, back, joint, or muscle pain
  • dizziness
  • fatigue
  • fluid retention
  • headache
  • hot flashes, night sweats
  • nausea
  • weight gain

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.


Last Updated: February 27, 2009
Licensed from
The Healthline Site, its content, such as text, graphics, images, search results, HealthMaps, Trust Marks, and other material contained on the Healthline Site ("Content"), its services, and any information or material posted on the Healthline Site by third parties are provided for informational purposes only. None of the foregoing is a substitute for professional medical advice, examination, diagnosis, or treatment. Always seek the advice of a physician or other qualified healthcare provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on the Healthline Site. If you think you may have a medical emergency, call your doctor or 911 immediately. Please read the Terms of Service for more information regarding use of the Healthline Site.
Advertisement
Advertisement