Letrozole, sold under the brand name Femara among others, is an aromatase inhibitor which is used in the treatment of hormonally-responsive breast cancer after surgery.
Letrozole is approved by the United States Food and Drug Administration (FDA) for the treatment of local or metastatic breast cancer that is hormone receptor positive or has an unknown receptor status in postmenopausal women.
Femara is available in generic form.
Common side effects of Femara include:
- hot flashes,
- warmth in your face or chest,
- hair loss,
- joint/bone/muscle pain,
- unusual sweating or night sweats,
- trouble sleeping,
- weight gain,
- flushing (warmth, redness, or tingly feeling),
- numbness/tingling/weakness/stiffness in your hand or fingers, or
- pain in your hand that spreads to your arm, wrist, forearm, or shoulder.
How Letrozole Is Given:
- Letrozole is a pill, taken by mouth.
- You should take Letrozole at about the same time each day. You may take Letrozole with or without food. If you miss a dose, do not take a double dose the next day.
- You should not stop taking Letrozole without discussing with your physician.
- The amount of Letrozole that you will receive depends on many factors, including your general health or other health problems, and the type of cancer or condition being treated. Your doctor will determine your dose and how long you will be taking Letrozole.
Who should NOT take this medication?
Do not take letrozole if you:
- are allergic to letrozole or any ingredients of the medication
- are allergic to any other aromatase inhibitor medications (e.g., anastrozole, exemestane)
- are breast-feeding
- are pregnant
- are premenopausal
- are under 18 years of age
Letrozole and pregnancy
Studies conducted so far have shown either no increased risk of miscarriage or a decrease in miscarriage risk. Letrozole is considered pregnancy Category D. Letrozole should not be given to women who are already pregnant. Studies in rats and mice have shown that letrozole increases the risk of fetal death and malformations. Since there are no studies in human beings, it should be assumed that a similar effect is possible.
What special precautions should I follow?
Before taking letrozole,
- tell your doctor and pharmacist if you are allergic to letrozole, any other medications, or any of the ingredients in letrozole tablets. Ask your pharmacist for a list of the ingredients.
- tell your doctor and pharmacist what other prescription and nonprescription medications, vitamins, nutritional supplements, and herbal products you are taking or plan to take. Be sure to mention any of the following: medications that contain estrogen such as hormone replacement therapy (HRT) and hormonal contraceptives (birth control pills, patches, rings, and injections); raloxifene (Evista); and tamoxifen (Nolvadex).
- tell your doctor if you have high cholesterol, osteoporosis (condition in which the bones are fragile and break easily), or liver disease.
- you should know that letrozole should only be taken by women who have experienced menopause and cannot become pregnant. However, if you are pregnant or breast-feeding, you should tell your doctor before you begin taking this medication. Letrozole may harm the fetus.
- you should know that letrozole may make you drowsy. Do not drive a car or operate machinery until you know how this medication affects you.