Care During Chemotherapy and Beyond


(an AS troe zole)

Generic Name: Anastrozole

Trade Name: Arimidex®

Anastrozole is the generic name for the trade name drug Arimidex®. In some cases, health care professionals may use the trade name Arimidex® when referring to the generic drug name Anastrozole.

Drug Type:

Anastrozole is an anti-cancer hormone therapy. This medication is classified as a "non-steroidal aromatase inhibitor" (For more detail see "How Anastrozole Works" below).

What Anastrozole Is Used For:

  • Anastrozole is used to treat breast cancer in postmenopausal women.

Note: If a drug has been approved for one use, physicians sometimes elect to use this same drug for other problems if they believe it might be helpful.

How Anastrozole Is Given:

  • Anastrozole is a pill, taken by mouth.
  • You should take anastrozole at about the same time each day.
  • You may take anastrozole with or without food.
  • If you miss a dose of anastrozole, take it as soon as you remember unless it is almost time for the next dose. Do not take a double dose to make up a missed dose.
  • You should not stop taking anastozole without discussing with your physician, even if you feel well.

The amount of anastrozole that you will receive depends on many factors, including your general health or other health problems, and the type of cancer or condition being treated. Your doctor will determine your dose and how long you will be taking anastrozole.

Side Effects:

Important things to remember about the side effects of anastrozole:

  • Most people do not experience all of the anastrozole side effects listed.
  • Anastrozole side effects are often predictable in terms of their onset, duration, and severity.
  • Anastrozole side effects will improve after therapy is complete.
  • Anastrozole side effects may be quite manageable: There are many options to help minimize or prevent the side effects of anastrozole.

The following side effects are common (occurring in greater than 30%) for patients taking Anastrozole:

The following side effects are less common (occurring in 10-29%) for patients taking anastrozole:

Not all side effects are listed above, some that are rare (occurring in less than 10% of patients) are not listed here. However, you should always inform your health care provider if you experience any unusual symptoms.

When To Contact Your Doctor or Health Care Provider:

Contact your health care provider immediately, day or night and go to the nearest emergency room, if you should experience any of the following symptoms:

  • New or worsening chest pain
  • Shortness of breath
  • Swelling of the face, lips, tongue and/or throat
  • Difficulty swallowing and/or breathing.

The following symptoms require medical attention, but are not emergency situations. Contact your health care provider within 24 hours of noticing any of the following:

  • Vaginal bleeding (similar to a period)
  • Tickling, Tingling, or Numbness of your skin
  • Nausea (interfering with ability to eat and unrelieved with prescribed medication)
  • Vomiting (vomiting more than 4-5 times in a 24 hour period)
  • Yellowing of your skin or the whites of your eyes
  • Pain on the right side of your stomach-area

Always inform your health care provider if you experience any unusual symptoms.


  • Before starting anastrozole treatment, make sure you tell your doctor about any other medications you are taking (including over-the-counter drugs, vitamins, or herbal remedies)
  • Anastrozole interacts with certain medications. Make sure you tell your doctor if you are taking these medications:
    • Tamoxifen
    • Estrogen
    • Warfarin
    • Estrogen/estradiol-containing medications (commonly used for menopause and birth-control)
  • Before starting anastrozole treatment, make sure you tell your doctor about health conditions you have including: heart conditions, osteoporosis, and abnormal cholesterol. Anastrozole may cause increased risk for heart disease. Talk with your healthcare provider to weigh the benefit and risks.
  • Inform your health care professional if you have not had menopause yet (premenopausal).
  • Inform your health care professional if you are pregnant or may be pregnant prior to starting this treatment. Anastrozole is pregnancy category X (anastrozole may be hazardous to the fetus. Anastrozole is contraindicated in women who are pregnant or may become pregnant).
  • Anastrozole may enter breast milk. It is unclear what effect this may have on babies. Tell your doctor if you are breastfeeding or plan to breastfeed.

Self Care Tips:

  • If you experience hot flashes, wearing light clothing, staying in a cool environment, and putting cool cloths on your head may reduce symptoms. Consult your health care provider if these worsen, or become intolerable.
  • Acetaminophen or ibuprofen may help relieve discomfort from generalized aches and pains. However, be sure to talk with your doctor before taking it.
  • Anastrozole causes little nausea. However, to reduce nausea, take anti-nausea medications as prescribed by your doctor before taking it.
  • Good health practices such as getting plenty of rest and eating a healthy diet along with regular exercise are recommended
  • If you experience symptoms or side effects, be sure to discuss them with your health care team. They can prescribe medications and/or offer other suggestions that are effective in managing such problems.

Monitoring and Testing While Taking Anastrozole:

You will be checked regularly by your doctor while you are taking anastrozole, to monitor side effects and check your response to therapy. No additional blood work or tests are required for anastrozole.

How Anastrozole Works:

Hormones are chemical substances that are produced by glands in the body, which enter the bloodstream and can cause effects in other parts of the body. For example, the hormone testosterone is made in the testicles and is responsible for male characteristics such as deepening voice and increased body hair. The use of hormone therapy to treat cancer is based on the observation that cancer cell growth can partially depend on hormone binding to receptors on the cancer cell surface.

Hormone therapies can work through methods such as stopping the production of a certain hormone or interfering with hormone binding to the cancer cell receptor. The different types of hormone therapies are categorized by their function and/or the type of hormone that is affected.

Anastrozole is an aromatase inhibitor. This means it blocks the enzyme aromatase (found in the body's muscle, skin, breast and fat), which is used to convert androgens (hormones produced by the adrenal glands) into estrogens. Tumor cells dependent on estrogens grow less when there is no estrogen.

Note: We strongly encourage you to talk with your health care professional about your specific medical condition and treatments. The information contained in this website is meant to be helpful and educational, but is not a substitute for medical advice. is designed to provide the latest information about chemotherapy to patients and their families, caregivers and friends. For information about the 4th Angel Mentoring Program visit