Letrozole (Generic Name)

Other Names: Femara

About This Drug

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

Possible Side Effects (More Common)

  • Nausea
  • Hot flashes or night sweats
  • Joint or muscle pain or muscle weakness
  • Back pain
  • Increase in your cholesterol levels
  • Headache
  • Difficulty catching your breath
  • Changes in how strong your bones are. Your doctor may order a bone density test.

Possible Side Effects (Less Common)

  • Diarrhea
  • Vomiting
  • Increased blood pressure
  • Trouble sleeping
  • Rash
  • Pain in the breast
  • Dizziness
  • Swelling of your legs, ankles and/or feet
  • Blood clots (rare). A blood clot in your leg may cause your leg to swell, appear red, and feel warm, and/or cause pain. A blood clot in your lungs may cause shortness of breath, pain when breathing, and/or chest pain.

Treating Side Effects

  • Ask your doctor or nurse about medication that is available to help prevent or lessen nausea, vomiting, headache, and joint or muscle pain.
  • Do not put anything on your rash unless your doctor or nurse says you may. Keep the area around the rash clean and dry.
  • Let your doctor know if you have trouble sleeping.
  • Drink 6-8 cups of fluids every day unless your doctor has told you to restrict your fluid intake due to another medical condition. A cup is 8 ounces of fluid. If you vomit or have diarrhea, you should drink more fluids so that you do not become dehydrated.

Important Information

  • Swallow the pill whole. 
  • Do not chew, break or crush it.
  • You can take the pill with or without food. If you have nausea, take it with food.

Food and Drug Interactions

There are no known interactions of letrozole with food. This drug may interact with other medication. Tell your doctor and pharmacist about all the medication and dietary supplements (vitamins, minerals, herbs and others) that you are currently taking. The safety and effectiveness of dietary supplements and alternative diets are often unknown. Using these might unexpectedly affect your cancer or interfere with your treatment. Until more is known, you should not use dietary supplements or alternative diets without your cancer doctor's advice.

When to Call the Doctor

Call your doctor or nurse immediately if you have any of the following symptoms:

  • Difficulty catching your breath
  • Pain when breathing
  • Coughing up blood
  • Chest pain. If it lasts 2 minutes or longer, call 911.
  • Feeling like your heart is racing (palpitations)
  • Cramping, pain, swelling, redness and/or warmth of leg
  • Uncontrolled nausea that prevents you from eating or drinking
  • Vomiting more than three times in one day
  • Dizziness

Notify your doctor or nurse as soon as possible if you have any of the following symptoms:

  • Diarrhea more that 4 times a day or diarrhea with weakness or lightheadedness
  • Nausea unrelieved by prescribed medication
  • Pain or headache that is not helped with medicines ordered by your doctor.
  • Weight gain of 5 pounds or more in 1 week
  • Swelling of your legs, ankles and/or feet
  • Muscle weakness that interferes with normal activities
  • Abdominal pain
  • Persistent loss of appetite or loss of 5 pounds or more in 1 week
  • Extreme tiredness that interferes with normal activities
  • Rash that is bothersome

Sexual Problems and Reproductive Concerns

  • In men and women both, this drug may temporarily or permanently affect your ability to have children. This cannot be determined before your therapy. Speak with your doctor or nurse if you plan to have children. Ask for information on sperm or egg banking.
  • In men, this drug may interfere with your ability to make sperm, but it should not change your ability to have sexual relations.
  • In women, menstrual bleeding may become irregular or stop while you are receiving this drug. Do not assume that you cannot become pregnant if you do not have a menstrual period.
  • Women may experience signs of menopause like vaginal dryness or itching. Vaginal lubricants can be used to lessen vaginal dryness, itching, and pain during sexual relations.
  • Genetic counseling is available to you to discuss the effects of this drug therapy on future pregnancies. In addition, a genetic counselor can review the potential risks of problems in the fetus due to this medication if an exposure during pregnancy has occurred.
  • Pregnancy warning: This drug may have harmful effects on the unborn child, so effective methods of birth control should be used during your cancer treatment.
  • Breast feeding warning: Women are advised not to breast feed during treatment because this drug could enter the breast milk and seriously harm a breast feeding infant.

Revised June 2013________________________________________

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