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( an-AS-tra-zawl )
ODB Limited Use
  • anastrozole - For the treatment of metastatic breast cancer in hormone receptor positive post-menopausal women
  • anastrozole - An alternative to tamoxifen for the adjuvant treatment of postmenopausal women with hormone receptor positive breast cancer
Other Name(s): Arimidex® (multiple brands available)
Appearance: tablet

Medication Information Sheet
anastrozole (an-AS-tra-zawl)
This document provides general information about your medication. It does not replace the advice of your health care professional. Always discuss your therapy with your health care professional and refer to the package insert for more details.

Other Name: Arimidex®


What is this medication for?
  • For treating hormone sensitive breast cancer in women after menopause.
What should I do before I have this medication?
    • Tell your doctor and pharmacist if you have / had problems that affect your heart, liver or kidneys, a personal or family history of osteoporosis/thin bones or related fractures or any allergies.
  • This drug contains a small amount of lactose. If you cannot tolerate lactose, talk to your doctor or pharmacist.
How is this medication given?
    • Anastrozole is usually taken once a day, at about the same time each day.

  • Swallow whole with a glass of water with or without food. Do no crush or chew.
  • If you miss a dose, take it if there are at least 12 hours until the next dose, otherwise skip and take your next dose as scheduled. Do not double the dose to make up for the forgotten one.

What else do I need to know while on this medication?
  • Make sure your health care team knows about all your medications (prescription, over-the-counter, herbals and supplements). Check with your health care team before starting or stopping any of them.

  • Do not take with tamoxifen or any treatment containing estrogen (including herbal supplements).


How should I safely store this medication?
  • Keep this medication in the original packaging at room temperature in a dry place, away from heat and light. Keep out of sight and reach of children and pets.

  • Do not throw out any unused medications at home. Bring them to your pharmacy to be thrown away safely.

What are the side effects of this medication?
The following side effects are common or severe. You may not have all of the side effects listed, while others not on this list may also occur. Discuss with your doctor if you have any unusual or bothersome symptoms.

Side effects and what to do When to contact doctor?
More Common Side Effects

Increased sweating, feelings of warmth (hot flashes)

  • Avoid triggers such as alcohol, caffeine (tea, coffee, cola), chocolate, hot & spicy food, stress and heat.
  • Exercise regularly. Keep cool; dress lightly; drink plenty of water.
  • May improve over time.

Other symptoms of having low estrogen levels

  • Vaginal dryness (possibly with discharge or bleeding)
  • Memory loss
  • Emotional effects (depression, for example)
  • Decrease in sexual desire
  • Contact your doctor or nurse if these feelings bother you.
Contact your health care team if no improvement or if severe

Joint, muscle pain or stiffness

  • Take painkiller(s) as directed, if given to you by your doctor.
  • Otherwise, take acetaminophen (Tylenol®) tablets as needed for mild aches and pains. Ask your doctor or pharmacist about the right dose for you.
  • Rest often, but may try light exercise.
Contact your health care team if no improvement or if severe

Tiredness or weakness

  • Rest often; take naps if needed. Move slowly when getting up.
  • Eat well-balanced meals and drink plenty of fluids. Light exercise may help.
  • Do not drive a motor vehicle or operate machinery when feeling tired.
Contact your health care team if no improvement or if severe

Nausea and vomiting (generally mild)

  • Drink clear fluids and avoid large meals. Get fresh air and rest.
  • Limit spicy, fried foods or foods with a strong smell.
  • Take anti-nausea drug(s) exactly as directed by your doctor. It is easier to prevent nausea than to treat it.
  • Contact your doctor if nausea lasts more than 48 hours or vomiting for more than 24 hours.
  • Also see Nausea & Vomiting pamphlet.*
Contact your health care team if no improvement or if severe

Bone pain; Bone loss

Bone fractures
(long-term effect)

  • Watch for any severe or unusual bone pain, including the back, hips, wrist, or other bone(s).
  • Your doctor may monitor your bone density periodically.
  • Anastrozole may increase the risk of bone loss or fractures. To help prevent this, your doctor may tell you to take calcium and vitamin D supplements or other prescription medications to treat osteoporosis. Talk to your doctor before taking these supplements.
  • Get emergency medical help if you experience a bone fracture (severe bone pain, unable to move)
  • Also see Bone Health in Postmenopausal Women* pamphlet.
Contact your health care team if no improvement or if severe

Rash, itchy skin

  • Stay out of the sun; wear sunblock, a hat and cover exposed skin.
  • Use daily moisturizer.
  • May be severe, including blisters and skin peeling; get emergency medical help right away if this occurs.
Contact your health care team if no improvement or if severe

Abnormal cholesterol or fat levels in the blood

  • Your doctor may monitor these regularly.
Contact your health care team if no improvement or if severe

Side effects and what to do When to contact doctor?
Less Common Side Effects, but may be Severe

Heart problems
(irregular heartbeat, chest pain, fainting, swelling, shortness of breath)

Get emergency medical help right away

Blood clot (limb pain or swelling, hardened vein in limb), may occur in lungs (sudden start of coughing, breathing problems, chest pain, coughing blood)

Blockage of an artery (blood vessel) in your heart, brain, chest, belly, or limbs; this may result in stroke (sudden loss of vision, speech, or the use of your limb(s)) or heart attack (chest pain, shortness of breath), or pain in chest, belly or limb

Get emergency medical help right away

Inflammation of blood vessels in the skin

Contact your health care team as soon as possible (office hours)

Changes (including cancer) to the womb lining
(unusual vaginal bleeding, persistent pressure or pain in the belly)

Contact your health care team if no improvement or if severe

Abnormal liver lab tests

  • Your doctor will monitor these regularly.  Call your doctor if you have yellowish skin or eyes, or unusual dark urine.
Contact your health care team if no improvement or if severe

Salt imbalances (for example, high calcium level in the blood)
(muscle twitching, severe weakness or cramping, confusion, irregular heartbeat)

Get emergency medical help right away

Allergic reaction (severe rash, itchiness, swollen face, lip or tongue, chest or throat tightness; may occur during or shortly after the drug is given)

Get emergency medical help right away

For more links on how to manage your symptoms go to

The information set out in the medication information sheets, regimen information sheets, and symptom management information (for patients) contained in the Drug Formulary (the "Formulary") is intended to be used by health professionals and patients for informational purposes only. The information is not intended to cover all possible uses, directions, precautions, drug interactions or side effects of a certain drug, nor should it be used to indicate that use of a particular drug is safe, appropriate or effective for a given condition.

A patient should always consult a healthcare provider if he/she has any questions regarding the information set out in the Formulary. The information in the Formulary is not intended to act as or replace medical advice and should not be relied upon in any such regard. All uses of the Formulary are subject to clinical judgment and actual prescribing patterns may not follow the information provided in the Formulary.