Generic Name: letrozole (LET roe zol)
Brand Name: 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 not listed in this medication guide.
What is the most important information I should know about letrozole?
You should not use letrozole if you have not gone completely through menopause.
What should I discuss with my healthcare provider before taking letrozole?
You should not use letrozole if you are allergic to it, or if you have:
if you have not gone completely through menopause.
To make sure letrozole is safe for you, tell your doctor if you have:
liver disease (especially cirrhosis);
osteoporosis, osteopenia (low bone mineral density);
high cholesterol; or
if you also take tamoxifen.
Although it is not likely that a postmenopausal woman would be pregnant, letrozole could harm an unborn baby. Do not take this medicine if you are pregnant or may become pregnant. Use effective birth control if you are not past menopause, and tell your doctor right away if you become pregnant during treatment.
It is not known whether letrozole passes into breast milk or if it could harm a nursing baby. You should not breast-feed while you are using letrozole.
How should I take letrozole?
Letrozole is usually taken once per day, or once every other day. Follow all directions on your prescription label. Do not take this medicine in larger or smaller amounts or for longer than recommended.
You may take letrozole with or without food.
While using letrozole, you may need frequent blood tests. 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 missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.
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?
This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.
This medicine can pass into body fluids (urine, feces, vomit). Caregivers should wear rubber gloves while cleaning up a patient's body fluids, handling contaminated trash or laundry or changing diapers. Wash hands before and after removing gloves. Wash soiled clothing and linens separately from other laundry.
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:
dizziness, drowsiness, weakness, tired feeling;
hot flashes, warmth in your face or chest;
bone pain, muscle or joint pain;
flushing (warmth, redness, or tingly feeling);
increased sweating; or
swelling, weight gain.
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.
See also: Side effects (in more detail)
What other drugs will affect letrozole?
Other drugs may interact with letrozole, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.
More about Femara (letrozole)
- Side Effects
- During Pregnancy
- Dosage Information
- Drug Images
- Drug Interactions
- Support Group
- Pricing & Coupons
- En Español
- 49 Reviews – Add your own review/rating
- Generic Availability
- Drug class: aromatase inhibitors
Related treatment guides
Where can I get more information?
- Your pharmacist can provide more information about letrozole.
- Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.
- Disclaimer: Every effort has been made to ensure that the information provided by Cerner Multum, Inc. ('Multum') is accurate, up-to-date, and complete, but no guarantee is made to that effect. Drug information contained herein may be time sensitive. Multum information has been compiled for use by healthcare practitioners and consumers in the United States and therefore Multum does not warrant that uses outside of the United States are appropriate, unless specifically indicated otherwise. Multum's drug information does not endorse drugs, diagnose patients or recommend therapy. Multum's drug information is an informational resource designed to assist licensed healthcare practitioners in caring for their patients and/or to serve consumers viewing this service as a supplement to, and not a substitute for, the expertise, skill, knowledge and judgment of healthcare practitioners. The absence of a warning for a given drug or drug combination in no way should be construed to indicate that the drug or drug combination is safe, effective or appropriate for any given patient. Multum does not assume any responsibility for any aspect of healthcare administered with the aid of information Multum provides. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the drugs you are taking, check with your doctor, nurse or pharmacist.
Copyright 1996-2012 Cerner Multum, Inc. Version: 6.03.
Date modified: June 01, 2017
Last reviewed: October 06, 2015