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Anastrozole Tablets

Anastrozole is a medication that treats breast cancer among people who have gone through menopause. It works by blocking estrogen production. This can stop tumor growth because some types of breast cancer need estrogen to grow. The brand name of this medication is Arimidex®.

What is this medication?

ANASTROZOLE (an AS troe zole) treats breast cancer. It works by decreasing the amount of estrogen hormone your body makes, which slows or stops breast cancer cells from spreading or growing.

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This medicine may be used for other purposes; ask your health care provider or pharmacist if you have questions.

COMMON BRAND NAME(S): Arimidex

What should I tell my care team before I take this medication?

They need to know if you have any of these conditions:

  • Bone problems
  • Heart disease
  • High cholesterol
  • An unusual or allergic reaction to anastrozole, other medications, foods, dyes, or preservatives
  • Pregnant or trying to get pregnant
  • Breast-feeding

How should I use this medication?

Take this medication by mouth with a glass of water. Follow the directions on the prescription label. You can take it with or without food. If it upsets your stomach, take it with food. Take your medication at regular intervals. Do not take it more often than directed. Do not stop taking except on your care team's advice.

Talk to your care team about the use of this medication in children. Special care may be needed.

Overdosage: If you think you have taken too much of this medicine contact a poison control center or emergency room at once.

NOTE: This medicine is only for you. Do not share this medicine with others.

What if I miss a dose?

If you miss a dose, take it as soon as you can. If it is almost time for your next dose, take only that dose. Do not take double or extra doses.

What may interact with this medication?

  • Estrogen and progestin hormones
  • Tamoxifen

This list may not describe all possible interactions. Give your health care provider a list of all the medicines, herbs, non-prescription drugs, or dietary supplements you use. Also tell them if you smoke, drink alcohol, or use illegal drugs. Some items may interact with your medicine.

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What should I watch for while using this medication?

Visit your care team for regular checks on your progress. Let your care team know about any unusual vaginal bleeding.

Using this medication for a long time may weaken your bones. The risk of bone fractures may be increased. Talk to your care team about your bone health.

You should make sure that you get enough calcium and vitamin D while you are taking this medication. Discuss the foods you eat and the vitamins you take with your care team.

Talk to your care team if you may be pregnant. Serious birth defects can occur if you take this medication during pregnancy and for 3 weeks after the last dose. You will need a negative pregnancy test before starting this medication. Estrogen and progestin hormones may not work as well while you are taking this medication. Contraception is recommended while taking this medication and for 3 weeks after the last dose. Your care team can help you find the option that works for you.

Do not breastfeed while taking this medication and for 2 weeks after the last dose.

This medication may cause infertility. Talk with your care team if you are concerned about your fertility.

What side effects may I notice from receiving this medication?

Side effects that you should report to your care team as soon as possible:

  • Allergic reactions—skin rash, itching, hives, swelling of the face, lips, tongue, or throat

Side effects that usually do not require medical attention (report to your care team if they continue or are bothersome):

  • Bone, joint, or muscle pain
  • Headache
  • Hot flashes
  • Nausea
  • Sore throat
  • Swelling of the ankles, hands, or feet
  • Unusual weakness or fatigue

This list may not describe all possible side effects. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Where should I keep my medication?

Keep out of the reach of children and pets.

Store at room temperature between 20 and 25 degrees C (68 and 77 degrees F). Get rid of any unused medication after the expiration date.

To get rid of medications that are no longer wanted or have expired:

  • Take the medication to a medication take-back program. Check with your pharmacy or law enforcement to find a location.
  • If you cannot return the medication, check the label or package insert to see if the medication should be thrown out in the garbage or flushed down the toilet. If you are not sure, ask your care team. If it is safe to put it in the trash, empty the medication out of the container. Mix the medication with cat litter, dirt, coffee grounds, or other unwanted substance. Seal the mixture in a bag or container. Put it in the trash.

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NOTE: This sheet is a summary. It may not cover all possible information. If you have questions about this medicine, talk to your doctor, pharmacist, or health care provider.

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Note: Introduction and Additional Common Questions written and medically approved by Cleveland Clinic professionals.

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