GENERIC NAME: LETROZOLE - ORAL (LET-tro-zole)
BRAND NAME(S): Femara
Medication Uses | How To Use | Side Effects | Precautions | Drug Interactions | Overdose | Notes | Missed Dose | Storage
USES: This medication is used to treat certain types of breast cancer (such as hormone-receptor-positive breast cancer) in women after menopause. Letrozole is also used to help prevent the cancer from returning. Some breast cancers are made to grow faster by a natural hormone called estrogen. Letrozole decreases the amount of estrogen the body makes and helps to slow or reverse the growth of these breast cancers.OTHER This section contains uses of this drug that are not listed in the approved professional labeling for the drug but that may be prescribed by your health care professional. Use this drug for a condition that is listed in this section only if it has been so prescribed by your health care professional.This medication may also be used to treat infertility in women.
HOW TO USE: Read the Patient Information Leaflet provided by your pharmacist before you start using letrozole and each time you get a refill. If you have any questions, consult your doctor or pharmacist.Take this medication by mouth, usually once daily with or without food or as directed by your doctor.Dosage is based on your medical condition and response to treatment.Use this medication regularly to get the most benefit from it. To help you remember, take it at the same time each day.Since this drug can be absorbed through the skin and lungs, women who are pregnant should not handle this medication or breathe the dust from the tablets. (See also Precautions section.)Inform your doctor immediately if your condition worsens (such as you get new breast lumps).
SIDE EFFECTS: Hot flashes, hair loss, joint/bone/muscle pain, tiredness, unusual sweating, nausea, diarrhea, dizziness, and trouble sleeping may occur. If any of these effects persist or worsen, notify your doctor or pharmacist promptly.Remember that your doctor has prescribed this medication because he or she has judged that the benefit to you is greater than the risk of side effects. Many people using this medication do not have serious side effects.Tell your doctor right away if you have any serious side effects, including: bone fractures, mental/mood changes (such as depression, anxiety), swelling of arms/legs, blurred vision, persistent nausea/vomiting, unusual tiredness, dark urine, yellowing eyes/skin..This medication (and cancer) may rarely cause serious problems from blood clots (such as heart attack or stroke). Get medical help right away if you experience: sudden shortness of breath, chest/jaw/left arm pain, confusion, coughing up blood, sudden dizziness/fainting, pain/swelling/warmth in the groin/calf, tingling/weakness/numbness in the arms/legs, slurred speech, weakness on one side of the body, vision changes, sudden/severe headache.A very serious allergic reaction to this drug is rare. However, get medical help right away if you notice any symptoms of a serious allergic reaction, including: rash, itching/swelling (especially of the face/tongue/throat/neck), severe dizziness, trouble breathing.This is not a complete list of possible side effects. If you notice other effects not listed above, contact your doctor or pharmacist.In the US -Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.In Canada - Call your doctor for medical advice about side effects. You may report side effects to Health Canada at 1-866-234-2345.
PRECAUTIONS: Before taking letrozole, tell your doctor or pharmacist if you are allergic to it; or to anastrozole; or if you have any other allergies. This product may contain inactive ingredients, which can cause allergic reactions or other problems. Talk to your pharmacist for more details.Before using this medication, tell your doctor or pharmacist your medical history, especially of: high blood fats (cholesterol), bone problems (such as osteopenia, osteoporosis), stroke or blood clots, heart disease (such as chest pain, heart attack, heart failure), high blood pressure, kidney problems, liver problems.This drug may make you dizzy and tired, and may rarely cause blurred vision. Do not drive, use machinery, or do any activity that requires alertness or clear vision until you are sure you can perform such activities safely. Limit alcoholic beverages.Before having surgery, tell your doctor or dentist about all the products you use (including prescription drugs, nonprescription drugs, and herbal products).This medication must not be used during pregnancy. It may harm an unborn baby. Letrozole is used mainly in women after menopause. If you have recently gone through menopause, discuss the need for use of reliable forms of birth control with your doctor. Do not use birth control products containing estrogen. Consult your doctor for more details. If you become pregnant or think you may be pregnant, tell your doctor immediately. (See also How to Use section.)It is not known whether this drug passes into breast milk and may harm a nursing infant. Breast-feeding while using this drug is not recommended. Consult your doctor before breast-feeding.
DRUG INTERACTIONS: Drug interactions may change how your medications work or increase your risk for serious side effects. This document does not contain all possible drug interactions. Keep a list of all the products you use (including prescription/nonprescription drugs and herbal products) and share it with your doctor and pharmacist. Do not start, stop, or change the dosage of any medicines without your doctor's approval.Some products that may interact with this drug include: estrogens (such as ethinyl estradiol, conjugated estrogens), estrogen blockers (such as anastrozole, tamoxifen).
OVERDOSE: If overdose is suspected, contact a poison control center or emergency room immediately. US residents can call their local poison control center at 1-800-222-1222. Canada residents can call a provincial poison control center.
NOTES: Do not share this medication with others.Laboratory and/or medical tests (such as bone density tests, cholesterol levels, liver function tests) should be performed periodically to monitor your progress or check for side effects. Consult your doctor for more details.This medication can increase the risk of bone loss (osteoporosis). Talk with your doctor about your risk, and about available treatments for osteoporosis. Lifestyle changes that reduce the risk of bone loss include doing weight-bearing exercise, getting enough calcium and vitamin D, stopping smoking, and limiting alcohol.

QUESTION
A lump in the breast is almost always cancer. See AnswerMISSED DOSE: If you miss a dose, take it as soon as you remember. If it is near the time of the next dose, skip the missed dose and resume your usual dosing schedule. Do not double the dose to catch up.
STORAGE: Store at room temperature away from light and moisture. Do not store in the bathroom. Keep all medications away from children and pets.Do not flush medications down the toilet or pour them into a drain unless instructed to do so. Properly discard this product when it is expired or no longer needed. Consult your pharmacist or local waste disposal company.
Information last revised January 2014. Copyright(c) 2014 First Databank, Inc.
Health News
- What Is Avascular Necrosis and How Does It Affect Bones?
- The Arch of the Human Foot Was Key to Upright Walking, Scientists Say
- Worried About Cataracts? Here's What You Need to Know
- FDA Issues Warning About Compounded Versions of Wegovy, Ozempic
- Sick Restaurant Workers Fuel Many Foodborne Illness Outbreaks
More Health News »
Health Solutions From Our Sponsors

Report Problems to the Food and Drug Administration
You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.
Selected from data included with permission and copyrighted by First Databank, Inc. This copyrighted material has been downloaded from a licensed data provider and is not for distribution, except as may be authorized by the applicable terms of use.
CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.
Top letrozole Related Articles
Breast Cancer
Breast cancer is an invasive tumor that develops in the mammary gland. Breast cancer is detected via mammograms, breast self-examination (BSE), biopsy, and specialized testing on breast cancer tissue. Treatment of breast cancer may involve surgery, radiation, hormone therapy, chemotherapy, and targeted therapy. Breast cancer risk may be lowered by managing controllable risk factors.
What you should know about breast cancer
- Breast cancer is the most common cancer among American women.
- One in every eight women in the United States develops breast cancer.
- There are many types of breast cancer that differ in their capability of spreading (metastasize) to other body tissues.
- The causes of breast cancer are unknown, although medical professionals have identified a number of risk factors.
- There are 11 common types of breast cancer and 4 uncommon types of breast cancer.
- Breast cancer early signs and symptoms include
- a lump in the breast or armpit,
- bloody nipple discharge,
- inverted nipple,
- orange-peel texture or dimpling of the breast's skin (peau d'orange),
- breast pain or sore nipple,
- swollen lymph nodes in the neck or armpit, and
- a change in the size or shape of the breast or nipple.
- Breast cancer can also be symptom free, which makes following national screening recommendations an important practice.
- Breast cancer is diagnosed during a physical exam, by a self-exam of the breasts, mammography, ultrasound testing, and biopsy.
- Treatment of breast cancer depends on the type of cancer and its stage (0-IV) and may involve surgery, radiation, or chemotherapy.
Drug Interactions
Drug interactions occur frequently. Get facts about the types of drug interactions, what substances or other things that may interact with drugs such as OTC drug and prescription drugs, vitamins, food(s) (grapefruit), and laboratory tests. Find out how to protect yourself from potential drug interactions.
Drugs: Questions to Ask Your Doctor or Pharmacist about Your Drugs
Important information about your drugs should be reviewed prior to taking any prescription drug. Side effects, drug interactions, warnings and precauctions, dosage, what the drug is used for, what to do if you miss a dose, how the drug is to be stored, and generic vs. brand names.Endometriosis
Endometriosis implants are most commonly found on the ovaries, the Fallopian tubes, the outer surfaces of the uterus or intestines, and on the surface lining of the pelvic cavity. They also can be found in the vagina, cervix, and bladder.Endometriosis Quiz
Endometriosis is a common gynecological condition. Take this quiz to learn what happens when a woman has endometriosis as well as causes, treatments, and risks.Inflammatory Breast Cancer
Inflammatory breast cancer is an accelerated form of breast cancer that is not usually detected by mammogram or ultrasound. Symptoms of inflammatory breast cancer include pain in the breast, skin change in the breast area, bruise on the breast,sudden swelling of the breast, nipple retraction or discharge, and swelling of the lymph nodes.Lapatinib (Tykerb)
Tykerb (lapantinib) is indicated in combination with capecitabine for the treatment of patients with advanced or metastatic breast cancer and other specific conditions. Tykerb (lapantinib) is also used in concert with letrozole for the treatment of postmenopausal women with hormone receptor-positive metastatic breast cancer with other conditions present.
megestrol (Megace, Megace ES)
Megestrol (Megace, Megace ES) is a drug prescribed for stimulating the appetite in patients with AIDS who have poor appetite or an unexplained significant weight loss. This medication is also used for treating breast cancer and weight loss associated with cancer. Review side effects, drug interactions, and pregnancy safety information prior to taking this medication.tamoxifen (Soltamox, Nolvadex)
Tamoxifen (Soltamox) is an anti-estrogen medication prescribed for the prevention and treatment of breast cancer in men and breast cancer in women. Tamoxifen also is prescribed to stimulate ovulation. Side effects include headache, vomiting, nausea, cough, fatigue, fluid retention, and bone pain.Breast Cancer Treatment by Stage
Treatment of breast cancer depends upon the stage of the cancer at the time of diagnosis. Some of the various treatments include:
- hormone therapy,
- radiation therapy,
- surgery,
- chemotherapy,
- HER2-targeted therapy,
- neoadjuvant therapy, and
- adjuvant therapy.