Letrozole Side Effects
What should I watch for?
Tell your doctor or healthcare professional if your symptoms do not start to get better or if they get worse.
Do not become pregnant while taking this medicine or for 3 weeks after stopping it. Women should inform their doctor if they wish to become pregnant or think they might be pregnant. There is a potential for serious side effects to an unborn child. Talk to your health care professional or pharmacist for more information. Do not breast-feed while taking this medicine or for 3 weeks after stopping it.
This medicine may interfere with the ability to have a child. Talk with your doctor or health care professional if you are concerned about your fertility.
Using this medicine for a long time may increase your risk of low bone mass. Talk to your doctor about bone health.
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.
You may need blood work done while you are taking this medicine.
Common and Rare Side Effects
Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur:
swelling of the feet or lower legs
Continuing or severe nervousness
dizziness or lightheadedness
pain in the chest, groin, or legs, especially the calves
severe and sudden, unexplained troubled breathing
severe, sudden headache
sudden loss of coordination
sudden, severe weakness or numbness in the arm or leg
Incidence not known
Black, tarry stools
burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
dilated neck veins
extreme tiredness or weakness
general tiredness or weakness
increased need to urinate
painful or difficult urination
passing urine more often
sores, ulcers, or white spots on the lips or in the mouth
unusual bleeding or bruising
unusual tiredness or weakness
upper right abdominal pain
white or brownish vaginal discharge
yellow eyes and skin
Some side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:
hot flashes (sudden sweating and feeling of warmth)
loss of appetite or weight loss
skin rash or itching
spinning or whirling sensation causing loss of balance
stomach pain or upset
Other side effects not listed may also occur in some patients. If you notice any other effects, check with your healthcare professional.
Call your doctor for medical advice about side effects. You may report side effects to the FDA at 1-800-FDA-1088.