Anastrozole (Arimidex®)

Printable PDF Version 

About This Drug

Anastrozole is used to treat cancer. This drug is given orally (by mouth.)

Possible Side Effects

  • Nausea and vomiting (throwing up)
  • Swelling of your legs, ankles and/or feet
  • Trouble sleeping
  • Weakness
  • Headache
  • Depression
  • Changes in mood
  • Inflammation of your nasal passages and throat
  • Lymphedema - swelling in your affected arm
  • Pain in the joints, arthritis
  • Fractures
  • Back pain
  • Pain
  • Osteoporosis -your bones may become weak and brittle.
  • Hot flashes or sudden skin flushing may happen. You may also feel warm or red.
  • Cough, trouble breathing
  • Rash
  • High blood pressure
  • Dilation (widening) of your blood vessels, which can cause low blood pressure

Note: Each of the side effects above was reported in 10% or greater of patients treated with anastrozole. Not all possible side effects are included above.

Warnings and Precautions

  • If you have a history of severe heart disease, this drug may increase your risk of a heart attack.
  • Decrease in your bone mass, which may put you at risk of bone fractures. Your doctor may monitor your bone mineral density.
  • Your total cholesterol level may increase.

How to Take Your Medication

  • Swallow the medicine with or without food.
  • Missed dose: If you miss a dose, take it as soon as you think about it. If it is close to your next
    dose, then skip the missed dose and go back to your normal schedule. Do not take 2 doses at the
    same time or extra doses.
  • Handling: Wash your hands after handling your medicine; your caretakers should not handle your
    medicine with bare hands and should wear latex gloves.
  • Storage: Store this medicine in the original container at room temperature.
  • Disposal of unused medicine: Do not flush any expired and/or unused medicine down the toilet or drain unless you are specifically instructed to do so on the medication label. Some facilities have take-back programs and/or other options. If you do not have a take-back program in your area, then please discuss with your nurse or your doctor how to dispose of unused medicine.

    Treating Side Effects

    • Drink plenty of fluids (a minimum of eight glasses per day is recommended).
    • If you throw up or have loose bowel movements, you should drink more fluids so that you do not become dehydrated (lack of water in the body from losing too much fluid).
    • To help with nausea and vomiting, eat small, frequent meals instead of three large meals a day. Choose foods and drinks that are at room temperature. Ask your nurse or doctor about other helpful tips and medicine that is available to help, lessen or stop these symptoms.
    • Keeping your pain under control is important to your well-being. Please tell your doctor or nurse if you are experiencing pain.
    • If you are having trouble sleeping, talk to your nurse or doctor on tips to help you sleep better.
    • If you are feeling depressed, talk to your nurse or doctor about it.
    • If you get a rash do not put anything on it unless your doctor or nurse says you may. Keep the area around the rash clean and dry. Ask your doctor for medicine if your rash bothers you.

    Food and Drug Interactions

    • There are no known interactions of anastrozole with food.
    • Check with your doctor or pharmacist about all other prescription medicines and over-the-counter medicines and dietary supplements (vitamins, minerals, herbs and others) you are taking before starting this medicine as there are known drug interactions with anastrazole. Also, check with your doctor or pharmacist before starting any new prescription or over-the-counter medicines, or dietary supplements to make sure that there are no interactions.
    • Avoid the use of estrogen containing products while taking anastrozole as this may lower the levels
      of the drug in your body, which can make it less effective.

    When to Call the Doctor

    Call your doctor or nurse if you have any of these symptoms and/or any new or unusual symptoms:

    • Fever of 100.4° F (38° C) or higher
    • Chills
    • Headache that does not go away
    • Blurry vision or other changes in eyesight
    • Feeling dizzy or lightheaded
    • Feel irritable, nervous or restless
    • Feeling depressed or hopeless, or abnormally well
    • Activities that you used to enjoy are no longer enjoyable
    • You feel hopeless on most days.
    • Tiredness or extreme weakness that interferes with your daily activities
    • Coughing up yellow, green, or bloody mucus.
    • Wheezing or trouble breathing
    • Chest pain or symptoms of a heart attack. Most heart attacks involve pain in the center of the chest that lasts more than a few minutes. The pain may go away and come back or it can be constant. It can feel like pressure, squeezing, fullness, or pain. Sometimes pain is felt in one or both arms, the back, neck, jaw, or stomach. If any of these symptoms last 2 minutes, call 911.
    • Nausea that stops you from eating or drinking and/or is not relieved by prescribed medicines
    • Throwing up more than 3 times a day
    • Weight gain of 5 pounds in one week (fluid retention)
    • Swelling of your legs, ankles and/or feet
    • New rash and/or itching
    • Rash that is not relieved by prescribed medicines
    • Pain that does not go away, or is not relieved by prescribed medicines
    • Tickling, tingling or numbness
    • If you think you are pregnant

    Reproduction Warnings

    • Pregnancy warning: This drug can have harmful effects on the unborn baby. Anastrozole should never be used by women who are pregnant or who could become pregnant while taking the drug. Women of child-bearing potential should use effective methods of birth control during your cancer treatment and for at least 3 weeks after treatment. Let your doctor know right away if you think you may be pregnant.
    • Breastfeeding warning: It is not known if this drug passes into breast milk. For this reason, women should not breastfeed during treatment and for 2 weeks after treatment because this drug could enter the breast milk and cause harm to a breastfeeding baby.
    • Fertility warning: In women, this drug may affect your ability to have children in the future. Talk with your doctor or nurse if you plan to have children. Ask for information on egg banking.

    Revised April 2019

    This patient information was developed by Via Oncology, LLC © 2019. This information is not intended to be used as a substitute for professional medical advice, diagnosis, or treatment. You should not rely entirely on this information for your health care needs. Ask your own doctor or health care provider any specific medical questions that you have. CLIENT acknowledges that the Via Pathways and Via Portal are information management tools only, and that Via Oncology, LLC has not represented the Via Pathways or Via Portal as having the ability to diagnose disease, prescribe treatment, or perform any other tasks that constitute the practice of medicine. The clinical information contained in the Via Pathways and Via Portal are intended as a supplement to, and not a substitute for, the knowledge, expertise, skill, and judgment of physicians, pharmacists and other healthcare professionals involved with patient care at CLIENT facilities.