Letrozole

Generic name: letrozole (LET roe zol)
Brand name: Femara
Dosage forms: oral tablet (2.5 mg)
Drug class: Aromatase inhibitors, Hormones / antineoplastics

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 not listed in this medication guide.

Warnings

You should not use letrozole if you are pregnant.

Before taking this medicine

You should not use letrozole if you are allergic to it.

letrozole is for use only in women who can no longer get pregnant. Letrozole can harm an unborn baby. Do not use if you are pregnant. Use effective birth control if you are not past menopause. Keep using birth control for at least 3 weeks after your last dose of letrozole. Tell your doctor if you think you may be pregnant.

Tell your doctor if you have ever had:

  • liver disease (especially cirrhosis);
  • osteoporosis, osteopenia (low bone mineral density);
  • high cholesterol; or
  • if you also take tamoxifen.

You should not breastfeed while you are using letrozole and for at least 3 weeks after your last dose.

How should I take letrozole?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

You may take letrozole with or without food.

You will need frequent medical tests, and your bone mineral density may also need to be checked.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Take the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not take two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking letrozole?

Avoid driving or hazardous activity until you know how letrozole will affect you. Your reactions could be impaired.

Letrozole side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Common side effects may include:

  • hot flashes, warmth or redness in your face or chest;
  • headache, dizziness, weakness;
  • bone pain, muscle or joint pain;
  • swelling, weight gain;
  • increased sweating; or
  • increased cholesterol in your blood.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Letrozole dosing information

Usual Adult Dose for Breast Cancer:

2.5 mg orally once a day

Duration of therapy:
-Adjuvant and extended adjuvant settings: Optimal duration is unknown; discontinue therapy at relapse.
-Advanced disease: Until tumor progression is evident.

Uses:
-Adjuvant treatment of postmenopausal women with hormone receptor positive early breast cancer
-Extended adjuvant treatment of early breast cancer in postmenopausal women who have received 5 years of adjuvant tamoxifen therapy
-First-line treatment of advanced breast cancer in postmenopausal women with hormone receptor positive or unknown locally advanced or metastatic breast cancer; second-line treatment of advanced breast cancer in postmenopausal women with disease progression following antiestrogen therapy

Usual Adult Dose for Breast Cancer -- Adjuvant:

2.5 mg orally once a day

Duration of therapy:
-Adjuvant and extended adjuvant settings: Optimal duration is unknown; discontinue therapy at relapse.
-Advanced disease: Until tumor progression is evident.

Uses:
-Adjuvant treatment of postmenopausal women with hormone receptor positive early breast cancer
-Extended adjuvant treatment of early breast cancer in postmenopausal women who have received 5 years of adjuvant tamoxifen therapy
-First-line treatment of advanced breast cancer in postmenopausal women with hormone receptor positive or unknown locally advanced or metastatic breast cancer; second-line treatment of advanced breast cancer in postmenopausal women with disease progression following antiestrogen therapy

What other drugs will affect letrozole?

Other drugs may affect letrozole, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.