Anastrozole (By mouth)


Anastrozole (an-AS-troe-zole)

Treats breast cancer.

Brand Name(s)


When This Medicine Should Not Be Used

How to Use This Medicine


  • Medicines used to treat cancer are very strong and can have many side effects. Before receiving this medicine, make sure you understand all the risks and benefits. It is important for you to work closely with your doctor during your treatment.
  • Take your medicine as directed.
  • Read and follow the patient instructions that come with this medicine. Talk to your doctor or pharmacist if you have any questions.
  • Missed dose: Take a dose as soon as you remember. If it is almost time for your next dose, wait until then and take a regular dose. Do not take extra medicine to make up for a missed dose.
  • If you vomit after taking your medicine, call your doctor or pharmacist for instructions.
  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any leftover medicine after you have finished your treatment. You will also need to throw away old medicine after the expiration date has passed.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Some medicines can affect how anastrozole works. Tell your doctor if you are taking any of the following:
    • Medicine that contains estrogen
    • Tamoxifen

Warnings While Using This Medicine

  • Pregnancy after menopause is not likely, but if you think you could be pregnant, tell your doctor. This medicine could harm an unborn baby.
  • Tell your doctor if you are breastfeeding, or if you have liver disease, bone problems (such as osteoporosis), high cholesterol, or heart disease.
  • This medicine may cause the following problems:
    • Increased risk for weak bones or osteoporosis
    • Increased cholesterol levels
    • Increased risk for heart attack or stroke
  • Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
  • Cancer medicines can cause nausea and/or vomiting in most people, sometimes even after receiving medicines to prevent it. Ask your doctor or nurse about other ways to control these side effects.
  • Keep all medicine out of the reach of children. Never share your medicine with anyone.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Back, bone, joint, or muscle pain
  • Blistering, peeling, or red skin rash
  • Chest pain or shortness of breath
  • Fever, chills, cough, sore throat, and body aches
  • Numbness, tingling, or burning pain in your hands, arms, legs, or feet
  • Rapid weight gain, or swelling in your hands, ankles, or feet
  • Severe diarrhea, nausea, or vomiting
  • Vaginal bleeding or discharge
  • Yellowing of your skin or the whites of your eyes

If you notice these less serious side effects, talk with your doctor:

  • Breast pain
  • Dizziness, headache, tiredness, or weakness
  • Mood changes, anxiety, or irritability
  • Trouble sleeping
  • Warmth or redness in your face, neck, arms, or upper chest

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Version Info

  • Last reviewed on 7/4/2015

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