Health Library

Anastrozole (By mouth)

Anastrozole (an-AS-troe-zole)

Treats breast cancer.

Brand Name(s):

Arimidex

When This Medicine Should Not Be Used:

How to Use This Medicine:

Tablet

• Your doctor will tell you how much medicine to use. Do not use more than 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.

Drugs and Foods to Avoid:

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

• Do not use this medicine together with tamoxifen.
• Some medicines can affect how anastrozole works. Tell your doctor if you are using medicine that contains estrogen.

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. Use an effective form of birth control during treatment with this medicine and for at least 3 weeks after the last dose.
• Do not breastfeed during treatment with this medicine and for at least 2 weeks after the last dose.
• Tell your doctor if you have liver disease, heart disease, bone problems (including osteoporosis), high cholesterol, or if you are still having your menstruation.
• This medicine may cause the following problems:
  • Increased risk for heart or blood vessel problems (including heart attack)
  • Loss of bone mineral density
  • High cholesterol in the blood
• 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.
• Talk with your doctor before using this medicine if you plan to have children. Some women who use this medicine have become infertile (unable to have children).
• Your doctor will do lab tests at regular visits to check on the effects of this medicine. Keep all appointments.
• Cancer medicine can cause nausea or vomiting, sometimes even after you receive medicine to prevent these effects. Ask your doctor or nurse about other ways to control any nausea or vomiting that might happen.
• 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 that may spread to your arms, jaw, back, or neck, trouble breathing, nausea, unusual sweating, fainting
• Dark urine or pale stools, loss of appetite, stomach pain, yellow skin or eyes

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

• Constipation, diarrhea, loss of appetite
• Dizziness, headache
• Tickling, tingling or numbness of your skin
• 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

Last Updated: 9/6/2024