Letrozole
Letrozole Oral tablet
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:
liver disease
osteoporosis (weak bones)
an unusual or allergic reaction to letrozole, other medicines, foods, dyes, or preservatives
pregnant or trying to get pregnant
breast-feeding
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:
estrogens, like hormone replacement therapy or birth control pills
This medicine may also interact with the following medications:
dietary supplements such as androstenedione or DHEA
prasterone
tamoxifen
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.
Where should I keep my medicine?
Keep out of the reach of children.
Store between 15 and 30 degrees C (59 and 86 degrees F). Throw away any unused medicine after the expiration date.
Updated:  
March 21, 2017
Sources:  
U.S. FDA-approved Package Insert