Letrozole (Femara®)

About This Drug

Letrozole is used to treat cancer. It is given orally (by mouth).

Possible Side Effects

  • Hot flashes or sudden skin flushing may happen. You may also feel warm or red.
  • Joint, muscle and bone pain
  • Headache
  • Weakness
  • Swelling of your legs, ankles and/or feet
  • Feeling dizzy
  • Increase in your cholesterol level. Your cholesterol will be checked as needed.
  • Increased sweating

Note: Each of the side effects above was reported in 20% or greater of patients treated with letrozole. Not all possible side effects are included above.

Warnings and Precautions

  • Decrease in your bone mass, which may put you at risk of bone fractures. Your doctor may monitor your bone mineral density.
  • Increase in your cholesterol level. Your cholesterol will be checked as needed.

Important Information

  • This drug may impair your ability to drive or use machinery. Use caution and tell your nurse or doctor if you feel dizzy or very sleepy.

How to Take Your Medication

  • Swallow the medicine whole with or without food.
  • Handling: Wash your hands after handling your medicine, your caretakers should not handle your medicine with bare hands and should wear latex gloves.
  • Storage: Store this medicine in the original container at room temperature. Discuss with your nurse or your doctor how to dispose of unused medicine.

Treating Side Effects

  • Keeping your pain under control is important to your well-being. Please tell your doctor or nurse if you are experiencing pain.
  • If you are dizzy, get up slowly after sitting or lying.
  • Keeping your pain under control is important to your well-being. Please tell your doctor or nurse if you are experiencing pain.

Food and Drug Interactions

  • There are no known interactions of letrozole with food.
  • This drug may interact with other medicines.
  • Tell your doctor and pharmacist about all the medicines and dietary supplements (vitamins, minerals, herbs and others) that you are taking at this time.

When to Call the Doctor

Call your doctor or nurse if you have any of these symptoms and/or any new or unusual symptoms:

  • Headache that does not go away
  • Pain that does not go away, or is not relieved by prescribed medicines
  • Weight gain of 5 pounds in one week (fluid retention)
  • Feeling dizzy or lightheaded
  • If you think you may be pregnant or may have impregnated your partner

Reproduction Warnings

  • Pregnancy warning: This drug may have harmful effects on the unborn baby. Women of child bearing potential should use effective methods of birth control during your cancer treatment and for at least 3 weeks after treatment. Let your doctor know right away if you think you may be pregnant.
  • Breastfeeding warning: Women should not breast feed during treatment and for 3 weeks after treatment because this drug could enter the breast milk and cause harm to a breast feeding baby.
  • Fertility warning: In men and women both, this drug may affect your ability to have children in the future. Talk with your doctor or nurse if you plan to have children. Ask for information on sperm or egg banking.

Revised September 2017